


Guardians

by SiderealMessenger



Series: Providence [2]
Category: Gravity Falls
Genre: M/M, Older Characters, human form Bill, human form demons
Language: English
Status: Completed
Published: 2015-07-28
Updated: 2015-08-30
Packaged: 2018-04-11 17:00:48
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 13
Words: 28,197
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4444448
Author URL: https://archiveofourown.org/users/SiderealMessenger/pseuds/SiderealMessenger
Summary: <blockquote class="userstuff">
              <p>Dipper and Bill always knew they wouldn't be able to keep their secret for long. But it's when they begin to suspect that Mabel is keeping a much darker secret of her own that their tenuous truce is tested. Yet Dipper will need Bill's help to figure out what is wrong with his sister, and Bill will need all the help he can get to deal with what they find. Because between demons, sibling rivalry isn't pretty.</p><p>~</p><p>"Once in many blue moons, a human is born who’s…linked, cosmically speaking, to a certain demon. As far as the universe is concerned, you’re mine. Our destinies are heavily interwoven. Call it providence.”</p><p>“I don’t believe in providence,” Dipper said. </p><p>“Yeah?” Bill asked, eye glinting with amusement. “Well, kid, it believes in you."</p>
            </blockquote>





	1. We Are Gathered Here Today

**Author's Note:**

> I just can't stop writing about these two.

**Notes for the Chapter:**

> Welcome to Guttermouth Falls. I don't know what happened.

“Oh God, I think I’m gonna be sick,” Dipper wheezed, leaning against the door frame of his attic room. His vision was starting to swim just a little, and he could not remember how to breathe normally for the life of him.

“I’ll be right beside you, Pine Tree,” Bill crooned, running his lithe, gloved fingers soothingly through Dipper’s hair. 

“Thanks, Bill,” Dipper sighed, leaning into the touch and beginning to calm a little. “I know you probably have better things to do than to sit through this.”

“Are you kidding?” Bill chuckled. “I wouldn’t miss you telling Stan Pines that his grandnephew’s been dating the demon lodger for a month right under his ugly nose for the world! You are so gonna get it, kid.”

Dipper swatted Bill’s hand away, betrayed. “You’re supposed to have my back on this!”

“Aw, kid, you know I do,” Bill said, about as tenderly as he was wont to say anything when mortal danger wasn’t immediately involved. For Bill, showing his feelings in any obvious way was like pulling teeth. No, scratch that, the dream demon had practically made teeth-pulling into a hobby. In any case, Dipper had accepted that Bill wasn’t about to start writing him sonnets any time soon, but Dipper _did_ expect Bill to be his ally, especially today. 

“But I’m a demon,” Bill continued. “I can’t help that I find conflict funny. It’s in my nature.”

“Your nature isn’t an excuse, Bill,” Dipper said, having gained the confidence to speak to Bill as an equal over the last month. Bill hadn’t flayed the skin from his flesh yet, despite that and many more creative threats. “Falling in love isn’t in your nature, and you did it anyway.”

“Whoa whoa whoa, Pine Tree. I never said the ‘L’ word,” Bill said stiffly. 

“You didn’t have to,” Dipper said. “I can tell.”

“What?! That’s a lie! There’s no way you can tell!” 

Dipper snickered. “I can now.”

“You little _brat_!” Bill hissed, gold, slitted eye flashing. “I will slit your stomach and feed you your own intestines ’til they look like the damn World Snake!”

“I’ll make you a deal,” Dipper said giddily. “You _don’t_ do that, and I don’t lock my door tonight.” Not that a locked door meant much to Bill anyway, but that wasn’t the point. 

Bill’s face slowly split into a smile. “Deal,” he said, holding out his hand as it ignited in blue flame.

“I’m not shaking on sex, Bill,” Dipper huffed in annoyance. 

Bill’s eye narrowed. “You’re despicable, kid. Maybe that’s why I love you.”

Dipper looked up at him in surprise, and it was only then that Bill realized what he’d said.

“Shit! That just slipped out. It proves nothing, Pine Tree!” 

Dipper gave Bill a shit-eating grin. “Sure, Cipher. I’ll see you downstairs.” 

With that, he swept open the door and strode down the hall to the stairs. If he could survive wringing a confession of love out of Bill Cipher, unwitting though it was, he could survive breaking the news to his Grunkle and the others. Even if he had just lost Bill as his backup on this, he knew he could count on Mabel to provide ground support. 

☆

“Attention, attention!” Mabel yelled, standing on her chair and banging her raised glass of Mabel Juice with a spoon as Grunkle Stan, Wendy and Soos sat down at the table, followed shortly by Dipper, and Bill a few seconds later. 

Dipper had asked her to call this Thursday Shack lunch so that he could tell their closest friends and family about Bill’s “nature” and his and the demon’s relationship. The thought of what he was about to do made him queasy all over again, eradicating nearly all of the confidence he’d gained from his conversation with Bill, but he knew it was better to get it over with sooner rather than later. These were not secrets he wanted to keep forever, or that he even could if he did want to. As exciting as it was, he was getting tired of he and Bill having to pull each other into closets and secret rooms just to get a moment alone together, and having to dance around each other when they were in the company of anyone other than Mabel. Dipper wanted everything out in the open, for better or for worse. 

“We are gathered here today–” Mabel continued.

“Whoa, who’s gettin’ married?” Grunkle Stan asked. 

“No one!” Dipper said quickly as Bill snickered beside him. “I asked Mabel to get everyone together because I have an announcement.” Dipper hauled in a breath, and exhaled his next words in an unbroken string: “I’msortofseeingsomeone.” 

“Cool, dude! Who is it?” Soos asked. 

“Yeah, spill the beans, Dipper,” Wendy goaded. 

Grunkle Stan kept Dipper under an even stare, his face betraying nothing. 

Dipper swallowed nervously. “Well, it’s someone you already know.” His gaze flicked briefly to Bill, and he caught the glint of mischief in the demon’s eye too late. Of course Bill would be out for retribution after Dipper had tricked him into talking about his feelings, and Dipper had presented him with the perfect opportunity. 

Dipper’s eyes widened, and he pleaded silently with Bill not to do whatever it was he was about to do. But Bill only grinned and, faster than Dipper had a hope of avoiding, clasped his hands around the back of Dipper’s head and pulled him in for a very wet and very sloppy kiss.

Dipper made a muffled, high-pitched sound of panic, but Bill held him fast, and Dipper realized that this way, at least he didn’t have to say anything. So he closed his eyes and let his awareness of place and time fade for a moment, giving in to the surprising comfort in the kiss. Maybe this really was Bill’s way of saying he was here for Dipper, come what may. After all, Bill, when it really came down to it, wasn’t a fan of words either. 

After a timeless moment, Dipper felt Bill’s grip loosen and he pulled back and opened his eyes. Looking around the table, Mabel was brimming with barely contained excitement, Wendy had a knowing look in her eyes and a slight smile, Soos began to applaud, and Grunkle Stan’s expression hadn’t changed at all, except for a worrying twitch in his eye. 

“So, uh, yeah,” Dipper began, then cleared his throat so that he didn’t sound so breathless. “B-Bill and I are...t-together.”

Wendy chuckled good-naturedly. “Hands raised if this is news to _anyone_ in this room.”

No one raised a hand except Soos, who thought about it for a moment, then shook his head and lowered it again, laughing. “Nope, never mind. Totally saw this one coming.”

“O-oh,” Dipper said, running a hand through his even messier than normal hair (courtesy of Bill). “Then, I guess, on to part two.”

“Part two?” Grunkle Stan ground out. “You two are not getting married.”

“No one’s getting married! I said that already!” Dipper yelled. 

“I dunno, Pine Tree, I think you’d look cute in white,” Bill purred. “Also in a dress.”

“Bill’s a demon!” Dipper blurted out. 

“Whoa, that escalated quickly,” Wendy said. “Bill was only joking…I think.”

“No, he’s an _actual_ demon,” Dipper said, taking a breath. “Wait, why am I the one in a dress?” he demanded of Bill. 

“Because I look fucking fabulous in a suit,” Bill replied easily. And Dipper really couldn’t argue.  

“There’s no such thing as demons, kid,” Grunkle Stan cut in. “That old book is filling your head with crazy.”

Bill casually snapped his fingers, and a vortex of blue flame spiraled into existence behind him, then opened to reveal a landscape of raging red fire and blood-curdling screams. All eyes fixed on the spectacle in astonishment and horror. Then Bill snapped again, and the blue flames closed around the scene and vanished, taking the screams with them. 

“ _Fuck me_ ,” Grunkle Stan breathed, the first to speak several long seconds later. 

“Afraid I’m rather engaged with your grandnephew in that department,” Bill said smugly.  

Grunkle Stan was up out of his chair and around the table surprisingly quickly for a man of his age, and Bill didn’t offer any resistance when Stan pulled him up by the lapels and slammed his fist into his face. In fact, Bill burst into laughter while Dipper shrieked in horror. He raised a gloved hand to his quickly bruising jaw and caught his breath. “That tickled,” he giggled. 

Grunkle Stan punched him again. The room erupted into chaos as Dipper and Mabel tried to haul their Grunkle off of Bill, Bill continued to laugh hysterically, Soos hid under the table and Wendy grabbed her axe, waiting to see who she needed to use it on (if they were human, she would use the blunt end). 

When the twins finally managed to corral everyone back to their seats at the table, it took a lot of honest, heartfelt words from Dipper and smooth talking from Bill to smother the fire of murder in Grunkle Stan’s eyes down to dull embers. Dipper assured the table that he, and everyone else in the room was safe with Bill – probably safer than anywhere else. Bill was the same person they had all gotten to know well over the past month; he just also happened to have the power to raze the town with a thought if he wanted to. Which he definitely didn’t, because Gravity Falls was his home, too. 

When it was time for the Mystery Shack to reopen after lunch, Grunkle Stan was willing to wait and see where things would go with the two of them, but he warned them that he’d be keeping an eye on them both for the slightest sign that Bill was a bad influence on Dipper. If anything, Wendy thought Bill was even cooler than before, and Soos was happy as long as Dipper was happy. 

For the most part, they fell back into their normal rhythm in the afternoon. Bill even helped out in the shop as a gesture of good faith. Grunkle Stan’s focus turned to Mabel when she forgot to restock the shelves for the second time that day, and Dipper breathed a sigh of relief. All in all, the day had gone…well, just about how he’d expected, really, but at least it hadn’t been worse. And now it was all behind him. 

After dinner, he kissed Bill goodnight in plain view, and headed up to his room with a smile probably as big and goofy as his sister’s plastered across his face. He only just remembered to leave the door unlocked before stripping down to his boxers and collapsing across the bed, exhausted. He’d close his eyes and rest, just for a little while, until everyone else was asleep…

☆

When Bill came into Dipper’s room an hour later, he huffed out a quiet laugh to see that the kid was out cold, sprawled across the bed, drool soaking into the sheet beneath his face. It had been a long day for the fragile little human. Carefully, he pulled the sheets over Pine Tree’s sleeping form, then slipped in beside him, settling in for a night of work in the Mindscape. 

“Sweet dreams, kid,” he murmured, and it was a promise. Then he reached over and turned off the light.


	2. Misunderstandings

Dipper came awake slowly, the tendrils of a dream filled with adventure but no danger snaking back from his consciousness and fading away. He didn’t open his eyes, instead mumbling something even he didn’t really understand and burying his face deeper into his pillow, hoping he could chase the remnants of the dream back into sleep. 

Except…since when had his pillow started feeling remarkably like a human torso? Or smelling pleasantly like deserts and ancient ruins? Like…Bill.

Dipper blearily opened his eyes and looked up to meet a single golden eye staring back.  

“You know, Pine Tree,” Bill said evenly, “I really do want to murder you in your sleep sometimes. I’m not supposed to find anything cute. It’s undignified for a demon. But that, what you just did? Fucking adorable.”

As Dipper’s awareness continued to transition to the waking world, he registered the fact that he was currently wrapped around Bill in a way that would make an opossum proud. This almost always happened when they slept in the same bed. Bill _radiated_ heat, and apparently Dipper’s subconscious was equipped with heat-seeking capabilities. 

Dipper decided dreamily that he didn’t really mind his pillow being Bill-shaped, and snuggled back against the demon, closing his eyes again. But he felt a strong hand pry his arm from around Bill’s middle and thread its fingers through his, pinning it to the mattress. Bill only had to shift his position slightly to be on top of Dipper. 

 “Ah ah, Pine Tree,” Bill said, gentle, but voice tantalizingly low. “You fell asleep last night before we got to have any fun. I’m not making that mistake again.”

Dipper was suddenly very awake and aware. His heart sped up and his skin tingled as Bill gently ran his nails down his bare chest – thankfully, they weren’t the impressive claws that the demon sometimes sported. Bill was being gentle, almost uncharacteristically so, but the direction in which this was going was obvious. And Dipper found he wasn’t at all opposed to the idea. 

Dipper shivered as Bill’s hand settled firmly on his hip, the other still pinning one of his own to the bed. With his free hand, he reached up and pulled Bill down into an open-mouthed kiss that became less and less sleep-sedated by the second. 

There was a loud knock on the door and Mabel’s voice danced cheerfully into the room. “Dipper, breakfast’s ready!”

They both groaned in frustration. “Ten more minutes, Shooting Star,” Bill called, before Dipper could think to stop him. He looked down at the flushed and lightly panting human beneath him and amended, “You know what? Five might do the trick.”

“Bill?” Mabel said, obviously not picking up on Bill’s meaning. “Sorry, no can do! I know how much you two love morning cuddles, but the pancakes are gonna get cold.” To Dipper’s horror, she flung open the door. 

It only took a second for her to register the scene and shriek, covering her burning face with her hands. “My eyes!” she cried. “Burning! That is _not_ morning cuddles!”  

“Mabel?!” Dipper gasped, shoving a cackling Bill off of him. “What the hell? Why did you come in when you knew Bill was here?”

“Why was the door unlocked?” she wailed. 

Well, she had Dipper there. “I, uh… You don’t wanna know.”

Dipper was astonished and appalled when the trembles from Mabel’s shock turned into a fit of barely restrained giggles. Apparently, Dipper was the only one truly embarrassed here as Mabel joined Bill in all-out laughter. He hated them both.  

“I’m so sorry, Brobro,” Mabel said, wiping a tear from the corner of her eye and still looking at the floor rather than at her brother and the demon in his bed. “Just, come downstairs when you’ve both put more clothes on.” Then she hastily retreated back downstairs.  

Bill was still gasping for air he didn’t need. “The look on your face, Pine Tree!” he cackled. “Hilarious! Like someone fired a gun next to your head!” 

“You have no shame, do you?” Dipper sighed, trying to calm his nerves.  

Well, the mood was effectively murdered and buried in the backyard. He got out of bed and quickly began to pull on jeans and a brick red t-shirt that had an 80% probability of being clean. Bill, whose clothes were in his own room, merely pulled the sleeping sweater Mabel had made for him (yellow with a black rendition of Bill’s triangle form smack in the middle – the demon was destined to love it) back on over his black pajama pants.  

“Kid, I would have you on the kitchen table at breakfast-time if you’d let me,” Bill replied, and Dipper couldn’t tell if he was joking.  

☆

Breakfast was incredibly awkward. Bill and Dipper had only slept together in the literal sense last night, but Dipper knew they didn’t look it, disheveled as they were. Grunkle Stan didn’t take his eyes off Bill the entire time. And Mabel couldn’t stop giggling. They were seventeen now, and still Dipper swore she acted like a twelve-year-old most of the time. He sighed, admitting to himself (though he would never admit it to her) that he wouldn’t have it any other way. 

After breakfast, Bill would have followed Dipper back up to his room, or the shower, but Grunkle Stan yelled “Hey, hell-spawn!” as soon as his hand touched the bannister.  

Bill’s head shot round at the address. “Yes, Mr. Pines?” He just barely managed not to growl the words.

“I need your help reaching some stuff on the top shelf in the stockroom,” Stan said, not bothering to conceal his ulterior motive of keeping the demon away from Dipper as much as possible. He couldn’t do much more than make things difficult for Cipher, but he could damn well excel at that. 

“The stepladder has disappeared, I take it?” Bill asked, looking straight at the stepladder resting in the corner of the next room. 

Grunkle Stan looked at it too, then back at Bill. “Off the face of the earth. It’s a mystery,” he shrugged. 

That time Bill really did growl, but it was difficult to be intimidating in one of Mabel’s fluffy sweaters and pajama pants, so he turned on his heel and took off in a huff in the direction of the stockroom. Grunkle Stan chuckled to himself in triumph and followed Bill to dictate all of the things he suddenly vitally needed from the top shelf where he only kept the stuff he knew he would never need. The worst part was, Grunkle Stan would probably make Bill put it all back again in a few days.

Dipper rolled his eyes at the exchange and continued up the stairs to take a shower. 

☆

Dipper was restocking the shelves with cheap merchandise when someone tapped him gently on the shoulder. He turned around to see a young woman of probably early college age standing behind him, holding one of the baseball caps with a blue pine tree on it. She smiled at him, and it was so honest and sweet that Dipper found himself smiling back automatically. 

“How much is this hat?” she asked, tucking a lock of blonde hair behind her ear unconsciously. 

“Should be six seventy-five, if my great uncle hasn’t decided to jack the prices up again since yesterday,” Dipper replied with a chuckle. 

“I’ll take it,” the girl said brightly. 

“You sure it’s really your style?” Dipper asked, taking in her nice, summery teal dress and gold flats. 

“Not my usual style, no,” the girl admitted, laughing herself. “But it looks so good on you, I thought I’d give it a try.”

“O-oh.” Dipper laughed nervously, suddenly understanding the situation he had found himself in, but unsure what to do about it. She seemed like a really nice girl after all, and Dipper didn’t want to hurt her feelings, or seem presumptuous if he was reading her signals wrong (because really, when had he ever been good at that? He was lucky Bill was so blunt.). “Thanks. And, uh, I’m sure anything would look good on you, so no worries. Wendy can ring you up at the register.”

Dipper looked over to see that Wendy was watching their exchange with a knuckle in her teeth, trying not to laugh. Dipper quickly turned back to the girl, who was still standing there, looking up at him expectantly. 

“Thanks for your help, and your fashion advice, um…?”

“D-Dipper,” he said quickly. 

“Is that your real name?” she asked with another bright smile. “It’s cute! I’m Dawn.”

“It’s not the one on my birth certificate, but it's the one I go by,” he said, stopping himself from rambling. “Dawn’s a nice name.”

“Thank you! So you must be a local, right Dipper?”

“Er, yeah, more or less…” Dipper said, certain he knew where this was going.  

“Then…can you show me a good place in town to get some coffee? When you get off work, that is?” She looked hopeful, but a little nervous, and Dipper really didn’t want to make that brilliant smile falter. 

“Uh…” he said, shifting his weight self-consciously. He wondered if the air conditioner had broken again; it was suddenly really warm.  

“You’re barking up the wrong tree, blondie,” Bill said, walking over to the two of them after deciding he’d had his fill of watching Pine Tree struggle from afar, and that the kid was in desperate need of a rescue. He pointedly slipped his hand into the teenager’s.  

“Oh!” the girl exclaimed, cheeks tinting rose-colored. “S-sorry,” she said, not sure which of them to address the apology to. Then she turned, bought the hat as quickly as she could, and left.  

“That wasn’t what it looked like,” Dipper groaned, wiping a hand over his face.  

Why did Bill have to pick _that_ moment to finally show up back at the Shack after whatever mysterious demonic errands he’d been running all day? Bill really didn’t spend much time at the Shack at all other than to see Dipper. He didn’t even spend most nights there. He was a busy demon, but whenever Dipper would ask for specifics, Bill would maneuver out of giving them, and Dipper would let him. He was Dipper’s boyfriend (and _man_ did that word sound weird in any way related to Bill Cipher), but he was also one of the creatures of Gravity Falls, and he was a mystery that could only be unraveled slowly. Dipper had already learned a lot about Bill in a short time, but he could fill journals on the demon and still not be satisfied. 

There was all that, and the fact that Dipper suspected Bill was still doomsday plotting on the side.  

“Really?” Bill said in a teasing tone. “Because it _looked_ like you’re still terrified to talk to girls who aren’t related to you.”

“Am not!” Dipper said, his voice embarrassingly close to a whine. He had never been able to take the high road and ignore Bill’s teasing. “And anyway, that was probably all just a misunderstanding.”

“Kid,” Bill sighed, “when are you going to realize that you’re hot stuff and everyone with at least one eye wants a piece of you?”

“W-What?” Dipper said, blushing and lowering his voice. They were at the other end of the gift shop now, leaning against the windowsill, but Wendy would still be able to hear them if they spoke above a low conversational tone. 

Bill followed Dipper’s gaze to the cashier and grinned. “Oh, I’ve even caught Red looking a couple of times. I didn’t need to read her mind to know that she was just about regretting ever turning you down.”

Dipper paled, all of the embarrassment of that painfully awkward moment from his adolescence returning in full force. “H-how do you know about that?”

“Kid, you grew up with me,” Bill said. “You just didn’t know it most of the time. And now, of course, you don’t remember.”

“Yeah, I keep forgetting that you’ve known me a lot longer than I remember knowing you,” Dipper said uneasily. “Were you really that bad? I mean, according to you, we were sworn enemies.”

“Well, that relationship was a little one-sided,” Bill chuckled, but when Dipper glared at him he put his hands up in surrender and began again earnestly. “I was pretty bad by human standards I suppose. But I didn’t hurt you… Well, I didn’t _kill_ you.”

Before Bill could dig himself any deeper of a hole, Mabel returned with the last tour group of the day, and Dipper went to meet her. “So, Sis, did you decide on our enriching cinematic experience for the evening? _El Chupacabra: The Legend is Real_ , or _The Man From Jupiter Who Ate My Face_?”

Mabel looked surprised. “Oh, Dipper you should have told me earlier. I already made plans with Candy and Grenda for tonight. We’re having a sleepover, and we’re gonna talk about boys, and I finally get to tell them all about you and Bill, and ohmigosh Candy’s gonna be _so_ jealous of you. We can watch a movie tomorrow, promise, but now I have to go up and pack my overnight bag in, like, two minutes, ‘cause they’re waiting for me outside! Love you, see you tomorrow, bye!” And Mabel was gone in her usual hyperactive and colorful flash.  

Dipper was left standing in the doorway to the Mystery Shack, rather dumbstruck. Finally he realized that Candy and Grenda were out in the front yard waving to him, and he mustered a wave back. 

“Hey, kid,” Bill said, suddenly behind him. “Which one do _you_ want to watch? Personally, I’d go with the face-eating, but that’s just me.”

“No, I uh, think I agree with you on that one,” Dipper said, still a bit dazed. 

He followed Bill back inside and dropped down onto the couch in the living room while Bill made (and burnt) popcorn. Almost mechanically, he fished the DVD out of the pile next to the TV and put it in. 

Grunkle Stan came into the room a few minutes into the movie and looked suspiciously over Dipper and Bill sitting shoulder-to-shoulder on the couch under a blanket and a bowl of burnt popcorn. “Where’s your sister?” he asked. “I thought Friday dumb movie night was a twin thing.” 

“It was– It _is_ ,” Dipper said slowly, not taking his eyes off the impressively terrible face-eating scene that Mabel would have been making grossed-out sounds at if she were there. “But she, uh, had other plans for tonight. I guess she just…forgot.” 


	3. Déjà Vu

Mabel returned to the Mystery Shack as Dipper and Grunkle Stan were finishing breakfast (Bill had had to leave after the movie was over, but he made and kept a promise to visit Dipper in his dreams that night). The moment she set foot in the kitchen she dropped her bag and made a beeline for her brother, catching him up in an asphyxiating but fuzzy hug.

“I’m so so so so sorry, Brobro,” she said into his shirt. “I don’t know how I forgot about dumb movie night. Jeez, why didn’t you stop me?”

Dipper laughed, relieved that Mabel really hadn’t intended to blow him off for some reason. “It’s okay, Mabs, Bill was willing to subject himself to alien face-eating horrors with me.”

She laughed with him. “Of course he was.”

“And it’s not like I want to keep you from your friends if you want to hang with them instead,” Dipper continued. 

“Whoa, hold up!” Mabel said, holding Dipper at arm’s length and giving him a stern look (or as much of one as she could ever manage). “You’re my best friend, Dipper. You always come first.”

Dipper’s eyes definitely weren’t tearing up at that. There was just a draft in the room. 

“Aw, and Shooting Star redeems herself,” Bill chimed, appearing out of nowhere beside the twins and startling them both. “But a warning for the future, kid: if you ever ditch Pine Tree for a slumber party again, there will be no slumber at that party. Not after the night terrors, anyway.” Bill’s smile didn’t falter. 

Mabel, like Dipper, had learned to treat Bill’s threats more like creative metaphors, but this seemed like one he might actually follow through with. She blinked. “Bill, was that a show of genuine affection for my brother? In your own weird, scary way?”

Bill scoffed. “Far from it, Shooting Star. I nobly endured one of your B movies with the phoniest screams, blood and gore I have _ever_ seen, but I won’t do it a second time. It's real screams, blood and gore or nothing for _this_ demon.”

“Yeah, but you didn’t _have_ to watch the movie with Dipper at all,” Mabel said with a knowing grin. 

“Bill, you _liked_ the movie,” Dipper pointed out. 

“Why do you two always have to gang up on me?” Bill whined. “I don’t have to endure this either,” he sniffed indignantly. “I’ll be back when you decide to do something interesting.” He vanished. 

“Dipper, your boyfriend PMS-es even more than I do,” Mabel said. 

Dipper groaned. “I know." 

“Oh, I almost forgot! Pacifica texted me an invite to her big eighteenth Birthday Ball! We should be getting the official invitation in the mail in a few days. We _have_ to go,” Mabel insisted. “I know you don’t like parties, Dip n’ Dots, but there’ll be _real_ dancing, and a fancy buffet, and Pacifica’s going to take me shopping for a party dress today— Oh, you need to go suit shopping!”  

“I heard suit shopping,” Bill said, reappearing and startling the twins yet again. 

“I have a suit,” Dipper said. 

“Kid, what you have isn’t a suit. It’s what an accountant would wear to a funeral,” Bill droned. 

Mabel gave Bill a conspiratorial look, and Bill grinned a little too evilly for Dipper’s liking. “He’s in good hands, Shooting Star,” he said, then grabbed Dipper before he could run and they both vanished in a flash of blue light. 

Mabel was left standing in the kitchen with Grunkle Stan, who had been sitting at the breakfast table watching the entire exchange. He grunted unintelligibly and resumed reading the newspaper. 

☆

Two more weekends brought the party. The time in between had been remarkably quiet on the mystery front, the twins only having to deal with one minor zombie rabbit uprising and a couple of renegade deer cats. Bill was Bill, and Grunkle Stan was Grunkle Stan, and there remained a tenuous and more-than-slightly antagonistic truce between them. At least Grunkle Stan was not above accepting a little more gold for a little more truce. 

Suit shopping had turned into Bill picking out Dipper’s outfit and Dipper having very little say in the matter. After all, Bill was the one with the gold (which Dipper was only somewhat surprised to see the local shopkeepers accept as legal tender) and the fashion sense. He ended up with slim black pants, a black button-down and a sharp, burgundy jacket. Thankfully, Bill let him veto the bowtie. He would _not_ start coordinating outfits with his demon boyfriend for all the gold in the world. 

Mabel had found a flowing, floor-length violet dress with a restrained hint of sparkle in the bodice and down the long, cream-colored gloves (picked out by Pacifica, Dipper guessed, but his sister wore them well). With Bill in his usual striking yellow coattails, black top hat and bowtie, the three of them made quite the picture. 

As usual, Dipper had a minor panic attack upon walking into the ballroom filled with so many sophisticated and social people laughing and talking and dancing, very few of whom he knew or even recognized. Understandably, most of the Northwests’ friends were from out of town, as very few people in Gravity Falls were deemed worthy of association with the family. 

Dipper had a death grip on Bill’s black-gloved hand, but the demon only found it amusing. At least one of them was enjoying himself. 

“I-I’ve never been a very good dancer,” Dipper said quietly. 

“That’s okay, Pine Tree,” Bill grinned, and for once, that confident, sharp-as-knives smile was reassuring. “Luckily for you, I am an excellent dancer. I once had a zombie as a dance partner, and if you’re half as good as a guy with rigor mortis who kept trying to bite me on the downbeats, I have more than enough to work with. And you, unlike my zombie friend, are welcome to bite me any time you want,” he said with a wink.

Dipper groaned at the terrible line, but couldn't stop himself from blushing regardless. As Bill began to drag him out onto the dance floor, he turned to wave a despairing goodbye to his sister, just in time to see Pacifica approach her and whisper something while keeping her eyes trained on him and Bill. Mabel’s face became one huge smile and she whispered excitedly back to Pacifica behind her gloved hand. Dipper knew his sister too well to even need to guess the topic of conversation. 

Surprisingly, after a few songs with Bill in the lead (and they were _good_ songs – Pacifica made sure that she had control of her party’s playlist, and the usual stuffy classical waltzes that smothered Northwest Manor party guests were replaced by contemporary, upbeat and interesting music that Dipper recognized very little of but greatly enjoyed) – Dipper found that he was no longer tripping over his own feet (or Bill’s), and began to relax. After a few more songs, he was actually starting to have fun. 

The other dancers recognized a superior talent in Bill (and perhaps mistook Dipper for having some, too, just by association) and gave the pair plenty of space, some even stopping to watch. But this didn’t bother Dipper, because he kept his eyes fixed on Bill’s, and Bill did the same. That wasn’t to say that the demon didn’t keep Dipper on his toes, dipping and spinning him unexpectedly just for the brief look of panic that would flash across his face and the way he would reflexively cling tighter to the demon – an opportunity that Bill always took to draw their bodies closer together and make Dipper blush, delighted that he could still do so with such ease. Still, Dipper found himself having the most fun at a Northwest party, or any party for that matter, that he could ever remember having. 

Mabel was enjoying herself, too. She and Pacifica had begun at the buffet table, chatting easily and gossiping up a storm, until Pacifica’s mother had called her away to receive her birthday present. She texted Mabel that it was the latest model Porsche, to replace the one she’d gotten on her sixteenth birthday, and said she was taking it out for a quick spin. 

Though Mabel had nearly exhausted the dating population of Gravity Falls’ young, eligible men, a few charming out-of-towners asked her for a dance, and she accepted every invitation. The song was just winding down for her dance with a dark and handsome exchange student named Marco who was deliciously European, when the boy was tapped on the shoulder by a delicate white-gloved hand. 

“Mind if I cut in?” a young woman in a sea-foam green and rose-colored dress asked. 

She had straight, platinum blonde hair even lighter than Pacifica’s, and a strange but beautiful star-shaped eyepatch that coordinated with the colors of her dress. Her other eye was an icy blue color that Mabel wasn't sure she had ever seen before on a person. Though she was almost certain she had never met this woman before, she still seemed vaguely familiar, like a case of déjà vu. 

Marco regretfully but gracefully bowed out, and the newcomer gently took Mabel’s hand. The woman’s hand was surprisingly cool, even through both of their gloves. 

“I’ve been admiring you from afar.” The woman had a smooth, melodic voice that somehow seemed to very faintly harmonize with itself. “You are very elegant, but it is also obvious that you have a strong, free spirit. That is a rare combination.”

“Uhm, thanks!” Mabel said, starting up the next dance with the woman. “Have we met before? You seem kinda familiar.”

“I tend to have that effect on people,” the woman laughed lightly. “But I am not from around here.”

“Where are you from?” Mabel asked. 

“Oh, a very different place,” the woman said, circling Mabel gracefully. 

Mabel’s eyes lit up. “Europe?” she breathed. 

The woman laughed again. “Something like that.” 

Mabel decided not to push further after the vague response. Her question didn’t seem to have hit a nerve with the woman, but a lot of people didn’t talk about their pasts for a lot of reasons, and Mabel respected that. 

“I love your eyepatch,” she said instead. “My brother’s boyfriend wears an eyepatch, and sure, it looks cool and mysterious in kind of an arcane, occult way – he’s, uh, really into that stuff – but yours is just… _beautiful_.”

“Thank you,” the woman said, her long, elegant fingers brushing the edge of the colorful patch. “Are the two of them here at the party as well?”

“Yeah, they’re around here somewhere,” Mabel chuckled. “Unless they’re making out in a closet or something. Hmm… I should maybe go make sure they’re _not_ doing that.”

“It can wait until we’ve finished our dance, surely?” the woman asked. “I made the egregious oversight of failing to even introduce myself. My name is Alexandra.”

“Wow, that’s a pretty name! I’m Mabel. And yeah, it can totally wait. It’s not like I’m in a hurry to catch my twin brother in a compromised position with that dapper devil again _anytime_ soon.”

“It sounds like they make quite the couple,” Alexandra commented. 

“Oh, you don’t know the half of it, sister!” Mabel grinned. “Bill will never admit it because he’s a weenie when it comes to expressing his feelings, but he’s totally in love with my brother. And Dipper’s always been a secret romantic sop, so he fell for Bill practically the day they met. As long as Bill keeps making him happy, I’ll let that dashing rogue stick around.”

“Well, that is something,” Alexandra mused. “I do hope you’ll give them my best.”

“Of course!” Mabel said, spinning under Alexandra’s raised arm. 

They continued talking as the music played on, but Mabel frequently found herself unable to remember the last thing she or Alexandra had said, and yet she was still able to carry on the conversation if she didn’t think too hard about it. Which she didn’t. She chalked the slightly weird experience up to the buzzing atmosphere of the party, and danced on. Alexandra was a great dancer – mesmerizing even – and Mabel was having too much fun to even think about calling it quits.  

As they danced, Mabel felt more and more content and at ease, moving across the dance floor almost as if in a dream. Everything seemed in soft focus, and miles away – even Alexandra. Then the colors slowly began to change and darken, and shapes morphed into different ones. When the tempo of the now soft music slowed and Mabel stopped spinning, the world regained some clarity, and then quickly regained more. 

Mabel took in a sharp gasp. She was in the middle of a battlefield. This wasn’t at all like the battlefields she’d seen in movies, glorified and dramatized, veiled in movie magic with deliberate design behind the chaos and carnage. This was real, and it was horrifying. Bodies were ripped and hacked to pieces as far as she could see, and the earth was ground up and swampy with warm but quickly cooling blood. The flies were swarming and the ravens spiraling overhead, and the stench alone should have been enough to overwhelm her senses and make her pass out. But she remained upright, bile rising in her throat but refusing to travel any further, and she couldn’t close her eyes and she _couldn’t stop dancing_ , even as flesh split and bones cracked under her dress heels. 

She was peripherally aware that this was a very distant time and place from where she had last been, but she could barely remember where that was. And she could remember this, though a part of her knew that she shouldn’t be able to. This scene with all its gruesome, violent death was intimately familiar, and she had the terrible, sickening knowledge that she had been the cause of it all. Even more sickening, however, was the part of her mind that relished in it, that whispered _victory_. 

Mabel fell to her knees in the middle of the ballroom and sobbed. She was alone. 


	4. Missing Pieces

Bill bit down hard on Dipper’s tongue, drawing blood. 

“Ouch! Bill!” Dipper yelped, holding a hand to his mouth. "What have I told you about how not everyone likes pain as much as you do?" Bill's fangs made kissing a hazard, but Dipper was the one who kept kissing him, so perhaps it was his own stupid fault in the end.

“Sorry, kid,” Bill said, already smoothing down his clothes and running a hand through his hair before replacing his top hat. “I just felt something. Something bad. We gotta go.” He held the closet door open for Dipper.

“What do you mean ‘something bad’?” Dipper asked in alarm as he followed Bill out into the hall, nearly having to jog to keep up. He didn't even bother with his hair – there was no salvaging it.

Before Bill could answer, they were back in the ballroom, and a space had cleared in the center of the dance floor as the guests formed a nervous circle around something. Dipper and Bill easily pushed their way to the front. 

“Mabel!” Dipper yelled, running to his sister who was sitting on the floor and shaking, sobs wracking her body and tears mingling with her makeup to form black streams down her face. “Are you hurt? What happened?” He knelt in front of her and put his hands on her shoulders, giving a tight squeeze. 

“I’m– I’m fine,” she said between sobs, smearing black tears away with her hands, staining her gloves black in the process. “I don’t even…remember…why I’m crying.”

“Pine Tree, get back,” Bill said tensely.

“What? No! I’m not leaving Mabel’s side while she’s like this,” Dipper said angrily, glaring up at Bill. 

“Kid, I’m going to help your sister, but something’s not right here and it could be dangerous, so just _do as I say_ ,” the demon growled. Then he took a short, controlled breath. “Please.”

Bill saying “please” was perhaps more worrying than reassuring, but it served to jar Dipper out of his panic, and he reluctantly stood back and let Bill take his place in front of Mabel. 

“Shooting Star, look at me,” Bill said. She did. “I’m going to calm you down, okay? You’re about to hyperventilate – believe me, I know the signs.” 

Mabel nodded her assent, though she was still trembling. Bill put a hand over her forehead, and Dipper was pretty sure no one noticed his and Mabel’s eyes glow faintly blue for a second. They were in Gravity Falls, after all – the townspeople were professionally unobservant. The next second, Mabel’s sobbing quickly diminished to occasional sniffles and her shaking stilled. She inhaled deeply and exhaled slowly, relief washing over her face. 

“Th-thanks, Bill,” she said. “I feel a lot better.”

Bill ignored her, keeping his hand on her forehead. “What’s the last thing you remember?” he asked. 

“I think…I was dancing with someone,” Mabel said, frowning, “but I’m not sure.” She looked around the circle of watching faces, but none of them seemed to be the one she was looking for. Not that she even knew what she was looking for. The words _‘I do hope you’ll give them my best’_ whispered at the edge of her memory. 

Bill stiffened. “Kid,” he breathed, “someone’s been messing with your mind. Specifically, your memory.”

“And it wasn’t you?” Mabel asked suspiciously. 

“Not this time,” Bill said. Then he slid one arm under her legs and the other behind her back and picked her up easily. 

“Wow, you’re strong,” she whispered, a familiar starry-eyed look coming over her face. She blinked and shook her head quickly. “They messed with my head, Bill, not my legs. I’m sure I can walk fine,” she said. 

“I take no chances, Shooting Star,” Bill said, already striding through the crowd towards the door. “I need to get a better look at you, where there aren’t so many people around. We’re going back to the Mystery Shack.”

Mabel sighed. “Well, it was a fun party while it lasted.” 

☆

Dipper drove while Mabel and Bill sat in the backseat, Bill watching Mabel like a hawk for any sign that something was off. When they arrived at the Shack, Bill allowed Mabel to walk from the car on her own, but ordered her to lie down on the couch in the living room as soon as they got inside. Luckily, Grunkle Stan seemed to have gone to bed already, or things would have been decidedly awkward. 

“Comfy, Shooting Star?” Bill asked. 

Mabel gave a thumbs up from her reclining position on the couch. Dipper watched nervously as the dream demon leaned over his sister and placed the tips of his fingers against her temples, just like when he’d taught them to shield their thoughts from the Illuminati. 

“Hey, Bill?” Mabel said casually, looking up at the demon innocently.

“Yes?”

“Where were you and Dipper earlier, during the party?” She absentmindedly twirled a lock of her hair. “I looked around and I couldn’t see you guys.”

“Bill—“ Dipper began.

“Oh, we were just heating up a hall closet, Shooting Star. You didn’t need to worry about us.”

Dipper smacked his forehead. 

“I knew it!” Mabel gasped. “I can’t take you two anywhere!”

“Now now, Shooting Star, relax,” Bill said, unperturbed. “If you don’t, you might end up a vegetable.”

“What?!” Mabel and Dipper demanded in unison. 

Bill threw his head back and laughed. “ _Man_ you two are gullible!”

“That’s not funny, Bill!” Dipper said. 

“Please, Pine Tree, I’m a master at this,” Bill replied, almost sounding offended. “I don’t turn anyone into a vegetable unless I want to.”

“Well that’s reassuring,” Dipper sighed. 

“Bill, have I told you lately how handsome and all-knowing and all-powerful you are?” Mabel said. 

Bill puffed up his chest. “Shooting Star, flattery will get you everywhere,” he grinned. “Now, close your eyes and try not to think of anything embarrassing while I poke around.”

Mabel shot one last doubtful look at Dipper, then did as Bill instructed. Bill replaced his fingers at Mabel’s temples, and closed his eye as well. Dipper fidgeted nervously. The seconds ticked by painfully slowly. Bill was eerily still. 

That is, until he leapt back with a yelp and continued to hover three feet in the air while shaking out his hands and muttering “ouch ouch ouch ouch” like he’d been shocked. 

Mabel’s eyes shot open in alarm. “What happened?” she asked. “Did it work?”

Bill regarded her warily. “Not exactly…”

“What does that mean?” she asked nervously. 

“Shooting Star, have you experienced anything…more unusual than normal lately?” Bill asked slowly. “Say, around three weeks ago?”

Mabel’s eyes darted between Dipper and Bill, betraying her growing unease. “I-I don’t know. I mean, we’re in Gravity Falls; unusual is like, the seven-day forecast.”

“You would remember this,” Bill said. 

Tears began to well in Mabel’s eyes again, but they didn’t fall. “I…don’t…”

“Or maybe you wouldn’t…” Bill murmured, more to himself than to anyone else. 

“Bill,” Mabel said, voice wavering. “Please tell me what you found.”

Bill fixed her with a level and unsympathetic stare. “There are small blank patches in your memory going back through the last three weeks. Tonight wasn’t the first time this thing has gotten its claws in your brain.”

“W-what? That’s not… I would _know_!” Mabel was shaking her head slowly now, disbelieving. 

Bill’s cool gaze defrosted just a little, and he shrugged. “Not necessarily.”

“Really? Because I think I’d notice if I just started forgetting things!” Mabel lashed back. 

“Like you forgot bad movie night with Pine Tree two weeks ago?” Bill asked calmly. “Or did you forget that you forgot that?”

Mabel’s frown deepened. “I just…wasn’t thinking that time.”

“Mabel,” Dipper said softly, “Grunkle Stan has been getting upset with you a lot more than usual lately for forgetting to do things around the Shack.”

Mabel’s gaze snapped to Dipper, and she looked betrayed. What made Dipper’s heart clench was that she tried to smile anyway. “You know me, Brobro… Since when have I ever listened to what Grunkle Stan tells me to do?”

“Why don’t you get some sleep, Shooting Star?” Bill suggested dispassionately. “Maybe I’ll think of something else to try in the morning.”

“That’s probably a good idea,” Dipper agreed. He helped Mabel up from the couch and gave her a tight hug, shooting Bill an angry look over her shoulder that the demon ignored. “We’ll figure this out. Promise,” Dipper whispered. 

Mabel sniffed and nodded weakly, then broke free of Dipper’s embrace and dashed up the stairs to her room. 

Dipper rounded on Bill. “Why were you talking to her like that?” he demanded. “If there really is something wrong with her memories, then it’s not like it’s her fault!”

Bill lowered his feet back onto the ground and looked down at Dipper, his temper obviously close to snapping. But Dipper could tell now that that was only a symptom of something affecting the demon on a much deeper level. 

“It very well might be her fault, _kid_ ,” Bill ground out, and the usually affectionate form of address was meant in its full patronizing and derisive potential. 

Dipper’s anger flared, but he forced himself to calm down. It wouldn’t help Mabel if both of them lost their tempers. “Bill, please just– Tell me what you’re thinking. I can’t read minds.”

For an infuriating moment, Bill looked like he wasn’t going to say anything more. But then he looked at Dipper again, _really_ looked this time, and some of his anger seemed to evaporate, some of his mysterious anxiety to settle.  “Pine Tree,” he sighed, “one of your sister’s memories was booby trapped. The nasty shock booted me right out of her head. And the only entity I know of that has that kind of talent for manipulating memories…” Bill trailed off uneasily. 

“Is what?” Dipper insisted. He hadn't even considered the possibility that there was something out there that was better than Bill at fucking with people's minds. Because he hadn't thought it  _was_ a possibility. 

“…is my sister,” Bill finished. 


	5. Family History

**Notes for the Chapter:**

> Alternate title: In Which the Author Hijacks Bill Cipher for Shameless Exposition and Still Isn't Sorry

“I wasn’t always the only one ruling the Mindscape,” Bill began. 

They were sitting on the bed in Dipper’s room now, at Bill’s insistence that they have this discussion somewhere more private. Bill had long since made sure that this room was well-protected from supernatural forces, and that included any possible unseen eavesdroppers. He really did not want this knowledge getting around. 

“My sister – if that’s what you want to call the other entity born from the fission of our original substance – was also a demon of the mind, drawing her power from the Mindscape. Where I specialized in dreams, she specialized in memories. We were a good team in the beginning.”

Dipper chewed his lip nervously at how Bill said “in the beginning” like the Bible said “in the beginning.” This was one of the “secrets of the universe” that Bill had always tempted him with, but never divulged. Usually, he said, because such secrets were too dangerous for humans to know. 

“But you know something of the kind of thinking you need to assert your will over the Mindscape,” Bill continued. “It’s divergent, you have to hold all possibilities from a given point in your mind at once, make something out of nothing, deal in negative space and pure ideas. You have to believe in things that don’t exist.”

“Basically, you have to be insane,” Dipper supplied. 

Bill grinned. “Exactly.”

“And two rulers requires coordination, order, in a place of essential chaos,” Dipper went on, thinking aloud.

Bill raised an eyebrow, but Dipper could tell he was impressed. “Do you want to finish the story, or should I?”

“No, go ahead,” Dipper said with an innocent smile. 

Bill rolled his eye. “You’re right, kid. We were bound to be at odds sooner or later. The first time it happened, we managed to come to an uneasy truce: she’d stick to her memories, and I’d keep to my dreams. We separated our domains. Things held for a while. Then, when humans began to get interesting, she thought it would be fun to get involved.”

“Like you’ve gotten involved?” Dipper said. 

“Yeah, yeah, the irony does not escape me,” Bill muttered. “Anyway, the Library of Alexandria was one of her pet projects. Or at least, I thought so at first. I didn’t see anything special about the place. We had access to far more knowledge than the humans would ever collect. But that wasn’t what the library meant to her. It was a collection of human memory, and she loved it, in her own way. To me, it was a huge building packed to the rafters with flammable material.”

Dipper’s eyes widened. “You didn’t.”

Bill shrugged. “I thought it would be funny. We hadn’t made any rules regarding the physical plane; it wasn’t like I was overstepping my bounds. And you know me, I can never resist a good bonfire.”

“Oh my god, my boyfriend burnt down the Library of Alexandria,” Dipper whimpered. “Bill, all of that lost knowledge… It’s one of the biggest mysteries in human history.”

“Well, mystery solved, kid!” Bill said, gesturing to himself.

“That’s only half the mystery! What was lost–“ Dipper cut himself off, realizing this was a tangent of secondary importance to Mabel’s current problem. “ _Ugh_ , go on. I’m guessing your sister was pissed.”

“HAHA! Understatement of the century, kid,” Bill laughed nervously. “She was downright murderous. Under almost any circumstances, neither of us can be killed without destroying the Mindscape, which would destroy us both. But we still had power over the Mindscape, which meant we had power over each other. She was willing to make herself very uncomfortable in order to hurt me, and then she came up with this plan to try to kill me by locking me inside one mortal’s mindscape. When the mortal died, which would be when she killed the poor bastard seconds later I’m sure, she thought I might die, too. And because there were two of us in those days, the Mindscape wouldn’t collapse – she could just fill my shoes and everything would keep on running.”

“Would that have worked?” Dipper asked. 

“I don’t know, kid,” Bill said. “But I wasn’t taking any chances. I got to her first. She'd picked up some idea of a code of combat from associating with the humans that I didn’t share. Her mistake was in declaring her intentions and giving me a fair warning. I reunited our domains and mustered full control of the Mindscape, banishing her from it then and there, and cutting off most of her power in the process. She still has a vital link to the Mindscape that I couldn’t sever without destroying the Mindscape with it, so she’s still alive, but she can’t enter or draw more power from the Mindscape than she needs to survive.”

“So…this feud is really all your fault,” Dipper said. 

“You could see it that way,” Bill replied. “Or you could see it as two forces in fundamental opposition, and the greater one overcame the lesser. Applying human terms to interactions that have nothing to do with humans tends to muddle things unnecessarily.”

“But she’s your sister!” Dipper said, horrified. 

Bill seemed unaffected. “See what I mean? ‘Sister’ is a human term. It isn’t an accurate description of her relation to me, and it adds meaning that isn’t there.” 

Bill may have had a point, but Dipper couldn’t tell. How was he supposed to know what the relation between primordial entities or the interactions of cosmic forces entailed? He could only understand things in human terms, and he kept coming back to the comparison of him and Mabel. He couldn’t even imagine them doing the things to each other that Bill had described. 

“All of that must have happened thousands of years ago,” Dipper sighed. “Why would she be causing trouble now, and what would she want with Mabel?”

“My best guess is that the two are related. Get out Journal #2,” Bill said. 

Dipper blinked. He had never trusted Bill with the journals, though he still wasn’t exactly sure why. He just had a strong gut feeling that Bill’s interest in the books was not well-meaning. 

“You can’t be serious,” he said. 

“You still don’t trust me with them, huh?” Bill said, more curious than offended. 

“No, I don’t,” Dipper said, somewhat apologetically. 

“Even after I erased your memories, a part of you still remembers,” Bill said in an amused tone. “You really must have had something for me if it left such a strong impression,” he grinned. 

Dipper didn’t return the smile. He didn’t like that he had had years of interactions with and feelings regarding the demon that he now could not remember. Even though Bill seemed honest when recounting the events of those years, admitting to some terrible things, Dipper still had to take the demon’s word for it. 

Bill sighed. “Your instincts are good, kid. I did try to steal and destroy your journals once because you were getting very efficient at using them to get in my way. But since we’ve been together I’ve told you more than those journals ever will. Because I’ve chosen to trust you. It’s up to you whether or not you choose to trust me, but it will be much easier for me to help your sister if you do.”

When put like that, was it really even a choice? Wordlessly, Dipper reached under his bed and unlocked the secret compartment, removing the second journal and placing it on the bed between him and Bill. He looked up into Bill’s single golden eye, daring him to make a wrong move. 

Bill didn’t break eye contact. “Open to my page.”

"How do you know there's a page on you?" Dipper asked, two parts stubbornness, one part suspicion.

"I'm Bill fucking Cipher, of course there's a page on me," Bill answered easily. 

Dipper snorted. He was only slightly embarrassed that Bill's page was the one that was bookmarked. He opened the journal to the familiar, red-spattered page on the dream demon Bill Cipher, then looked into the eye of the demon himself. 

“You’ve figured out what the symbols on my wheel stand for, haven’t you?” Bill asked conversationally. 

“I think…they’re all people in Gravity Falls,” Dipper answered. 

“Bingo, kid! Well, there’s one tiny technicality in there, but it’s irrelevant.”

It was tempting to press Bill on what he meant by a “technicality,” but Dipper did not need to remind himself again that Mabel was the priority. 

“The version of my wheel in this journal obviously isn’t very old,” Bill continued. “There are modern symbols in there like that plastic ice bag.” He was referring to the ice bag symbol in the upper right-hand portion of the wheel. Dipper wasn’t sure who that symbol represented yet. “The symbols on my wheel change once every hundred years, and each cycle represents a group of people who I am destined to cross paths with. Among that group, there are always a couple – and I mean exactly two – people who are even more special. Look at your symbol. What do you see?”

Dipper was about to fall back on his usual smart-assery that he reserved for whenever Bill was being frustratingly cryptic and say “a pine tree,” but he stopped himself. “Triangles,” he said. 

Bill’s eye seemed to glow a little brighter in the dim room. “Very good, Pine Tree. Now, you’ve heard of guardian angels, right?”

“Yes…” Dipper hedged. He was struggling to keep track of all of this new, seemingly unrelated information, and pleading silently that it would all come together soon. 

“Well, they don’t exist,” Bill said, and Dipper had to stop himself from groaning in frustration. “Angels have better things to do, usually involving creative new ways to screw us demons over. But once in many blue moons, a human is born who’s…linked, cosmically speaking, to a certain demon. Now don’t hit me for this, but technically, as far as the universe is concerned, you’re mine. Our destinies are heavily interwoven. Call it providence.”

“I don’t believe in providence,” Dipper said, definitely not beginning to panic. In the slightest. Whatsoever. 

“Yeah?” Bill asked, eye glinting with amusement. “Well, kid, it believes in you. But the fact that our destinies are intertwined doesn’t determine anything else about how our relationship goes. I could have chosen to be your guardian angel and protect you, I could have antagonized you, mentored you, used you, or…this thing with the feelings.” Bill laughed uncomfortably. “I actually ended up choosing all of them, I suppose.”

“Bill, where is all of this going?” Dipper finally had to ask. 

“I’m getting there, I promise. This is complicated stuff, Pine Tree,” Bill said. “A demon and the human who bears its symbol have the potential to be a huge force of change, even more than the demon on its own. That means you and I could really shake things up in this little tilted blue and green joint if we wanted to, Pine Tree. I've worked with Imhotep, Justinian, Flamel, da Vinci, Suleiman, Galileo, Tesla, you get the gist. You're in good company, kid." Dipper was trying his utmost not to make any embarrassing high-pitched sounds. How could Bill talk his ear off practically 24/7 and never have mentioned any of this? "The last such human that my sister worked with was Alexander the Great,” Bill continued.

“The Library of Alexandria,” Dipper realized, finally finding a connection. 

“Just an _after-effect_ of my sister and Alexander’s escapades,” Bill said. “I told you. Big force of change. Now, my sister’s true form is a star. Alexander’s symbol on my wheel back then was the Macedonian Star. There are two stars on my wheel this time around. The first is an actual rendition of my sister’s true form, and it belongs to that little pig-faced human, Gideon. But it’s only there because his family dabbled in black magic a few generations back and claimed my sister as their patron demon. They didn’t know that, thanks to yours truly, she was powerless to help them. Every bizarre achievement and fantastic screw-up that kid has made has been all his own doing, and a bit of mine. But the other star in my wheel belongs to—“

“Mabel,” Dipper breathed. 

“The Shooting Star,” Bill confirmed. “I think, if my sister wants to get back into the Mindscape and regain her power, your sister is her best shot.”

Dipper took a moment to think about all that Bill had told him. Slowly, he said, “You must have known something like this was going to happen. From the symbols.”

“I knew it _might_ ,” Bill said quickly. “But I had no idea _when_. My sister has left the last twenty-two humans destined to her after Alexander completely untouched. She was probably too weak for them to make much of a difference to her. Whatever the reason, I had hoped she would stay away from Shooting Star like she did the others.”

“Well hope obviously wasn’t enough, Bill! You should have told us! We could have prepared for this!” Dipper hissed, only because if he yelled he’d risk waking Mabel. 

“First, Pine Tree, I was going to tell you, but it’s only been a month and a half since we’ve been on the same team, and ideally, telling you all about my sordid history with my sister and mortal enemy would be something I’d warm up to,” Bill hissed back. “And second, you and Shooting Star have both been under my protection since the incident with the Illuminati, but my sister is so comparatively weak that my defenses can barely register her presence, let alone register her as a threat. There is nothing else I could have done short of hounding your sister day and night myself.”

It was difficult for Dipper to let go of his anger when there was so much of it and suddenly no direction for it to go, but Bill seemed to have done all he reasonably could to avoid this situation — and why wouldn’t he? He had as much to lose from his sister’s return as Dipper and Mabel did. 

“Okay,” Dipper exhaled. “I’m sorry. Hindsight’s 20/20, I know. I just want to focus on helping Mabel from now on.”

“Of course, kid,” Bill said softly. “But Shooting Star knows something about all this that she’s not telling us. You heard her downstairs. You two are terrible liars.”

“I know,” Dipper sighed. “I could tell, too. But I don’t understand why she’d try to hide this from us. From me.”

“Like I said downstairs, she may not know exactly what it is she’s hiding, or why. That’s an occupational hazard when you’re dealing with a demon of the mind. But we won’t know either unless we take a more…direct approach.”

“You aren't talking about—?” Dipper began, but before he could finish the question, Bill had slid a hand around the back of his neck, and the world started to darken. 

“See you in the Mindscape, kid!” was the last thing he heard before he blacked out. 


	6. A Trip Down Memory Lane

Dipper was about to give the demon a piece of his mind about pulling him without warning onto other planes of existence, but as soon as he found himself in the Mindscape, Bill grabbed his wrist and pulled him _sideways_ through reality into a different place. 

He recognized Mabel’s mindscape almost immediately, though he had never been here before. They stood before a towering, but oddly inviting castle, this structure curving gently where the archetypal medieval fortress would have sharp corners and spires. Patches of worn wood siding that Dipper would know anywhere bled through the stone masonry in places, giving the impression of a quilt of castle and Mystery Shack. 

There was a bizarre rumbling, _purring_ roar from high above, and Dipper looked up to see an enormous cat with the wings, horns, spines and talons of a dragon stir from its perch atop one of the buttresses. 

To Dipper’s horror, Bill threw out his arms and called “Here, kitty kitty!” and the dragon cat spread its wings and _dove_. 

Dipper shrieked and covered his eyes as the creature descended upon them with a deep, growling meow. When the reptilian purring started up again from very close by and Dipper found that he wasn’t in the process of being mauled, he lowered his hands from his face to see Bill scratching the creature underneath the chin, its eyes closed in a look of pure bliss. 

Bill was snickering, observing Dipper’s far from blissful expression. “Cupcake here’s completely harmless. Wanna pet her?”

Dipper, now that he had the time to properly observe the creature, noticed the enormous, rhinestone-studded plastic pet collar around its neck (Dipper had the nagging suspicion that the collar would be pink if there were any color in this place), the tag dangling from it indeed proclaiming the beast’s name to be Cupcake.

Cautiously, Dipper reached a hand out toward Cupcake, and she nuzzled into his palm with nearly enough force to knock him off his feet. Soon after Dipper got up the courage to scratch behind her ears, she pulled away, scrunching up her nose. When she sneezed, the patch of grass just in front of Dipper’s feet was scorched bare by a puff of flame. She looked back at Dipper with what he could have sworn was a smile, before crouching and springing into the air to circle above the castle. 

“Mostly harmless,” Bill amended, clapping Dipper on the back. “Come on, scaredy cat, time to invade your sister’s privacy!”

Dipper jogged after Bill across the drawbridge, noting that the moat surrounding the castle was filled with glitter and plastic dinosaurs. Mabel Juice. Dipper shivered, considering his sticky death by maceration if he were to fall in. 

“For the record, I never actually agreed to this,” he said.

“Noted,” Bill said, throwing open the enormous wooden doors as easily as if they were made of cardboard. “If Shooting Star ever finds out, you can say I threatened you with months of really gross dreams about your Grunkle if you didn’t go through with it.”

Dipper stopped. “ _Are_ you threatening that?”

Bill looked thoughtful. “I dunno. Are you suddenly feeling uncooperative?”

Dipper shuddered. “Nope! Let’s keep going,” he said, and walked quickly past Bill into the castle/Shack. 

The inside was just as confused as the outside, Dipper recognizing some rooms and hallways from the Mystery Shack interspersed among those of the unusually homey castle, and even some outdoor scenes of forest glades and lakeside beaches that somehow occupied indoor spaces. Of course, most surfaces and furniture items had been knit-bombed in vibrant patterns of different shades to make up for the absence of color. A family of ducks waddled past them down the long hallway, the last duckling hopping up onto Dipper’s shoe on its way past. He had to hold in the high, breathy sigh of adoration at how cute that was, or he would never hear the end of it from Bill.  

“So, mindmaster, where do we start looking?” Dipper asked, watching the ducks waddle off down the opposite hall.

“Do you know how vast and complex a person’s mindscape is, kid?” Bill replied. “Not to mention how navigating this _particular_ mindscape is practically an exercise in chaos theory? This is why I brought you along. You know your sister best. Where would she keep her darkest secrets?”

That was the last thing he wanted the dream demon to know. Bill was really asking for his trust going forward, and Dipper still didn’t see another option. Bill knew the mind and its demons, and Dipper knew Mabel. They needed to work together, which meant they needed to trust each other. Dipper gave a frustrated sigh.  _At least he’s the devil I know_ , he thought. 

Bill chuckled. “In the Biblical sense, Pine Tree.”

Dipper groaned. “Can you _please_ not make sex jokes while we’re in my sister’s head? It’s just weird.”

“Jeez, how did a fun-loving triangle like me end up with such a square?” Bill complained. 

“Geometry jokes…are okay,” Dipper said cautiously. 

“At least squares and triangles _tessellate_ just fine,” Bill continued with what Dipper could now easily tell was a wink.

“Nope, no more geometry,” Dipper said, grabbing Bill’s wrist and pulling the giggling demon down the hall behind him. “Mabel would feel really bad about keeping anything important from me,” he continued, returning to the relevant topic, “so whatever it is would be stuffed somewhere she wouldn’t have to think about it too much, somewhere she could almost hide it from _herself_ …”

“Remember, Pine Tree, this place is all metaphors,” Bill said, deciding to be helpful now. 

Dipper considered Bill’s guidance. “Well, as strange as this place is, it’s still basically a castle. I’m betting it has a dungeon.”

☆

Dipper could only take the dungeon so seriously when the signs on the thick, metal doors were lovingly crocheted, with little designs for embellishment. But other than the signs, the long, dark hallway of metal doors on either side, punctuated by narrow, sharp archways every fifty feet or so _was_ a bit intimidating. 

“Okay,” Dipper sighed, “you take the left side and I’ll take the right. Only open doors that sound like they might be what we’re looking for, and as soon as you know a memory _isn’t_ the one we’re after, close the door and move on. Are we clear?”

“Sir, yes, sir!” Bill said, giving a mocking salute. 

Dipper rolled his eyes and turned to the long row of doors on his right, vowing to keep an eye on Bill as he went. 

“Pine Tree,” Bill said seriously, stopping Dipper in his tracks. “You remember everything I’ve taught you about the Mindscape?”

Dipper nodded, recalling their frequent lessons at night after he closed his eyes. 

“All of that applies here, too,” Bill said. “You have access to less power in a personal mindscape, but you’re far from powerless.”

“Okay,” Dipper said, not sure he entirely understood what Bill was getting at. This place seemed to contain nothing but memories, but if Cupcake decided to venture down this far, Dipper was sure he could handle her. “I'll keep that in mind.”

After about two dozen doors with titles that Dipper was trying very hard not to remember (he felt that even reading the titles of these memories was a serious intrusion), he came to a door with a sign stitched – rather frantically it seemed – in red, that spelled in large capitals: THIS NEVER HAPPENED. And if that didn’t sound like serious repression, Dipper was the Queen of England. 

Slowly, he cracked open the door. He saw Mabel and Pacifica sitting on the purple shag rug in Mabel’s room, pillows, make-up and junk food scattered across the floor. Dipper knew a sleepover when he saw one. Whatever moment this was had probably been harmless, but Dipper had to be sure. He knew firsthand that no moment, however private or innocent, was immune from the unexpected dangers of Gravity Falls. Pacifica may be just about to get up to go to the bathroom or something, leaving Mabel alone with her thoughts. And with the demon they were after, that would be a perfect opportunity. 

“Dipper was right,” Mabel was saying forlornly, “every boy I take an interest in ends up being certifiably crazy or doomed to failure.”

“Ugh, tell me about it,” Pacifica replied. “I’m beginning to think they’re all complete losers.”

“Have you ever thought about…trying something…with a girl?” Mabel asked quietly. 

“Well, I…” Pacifica began. “Of course I have. Who hasn’t?”

“Yeah, who hasn’t?” Mabel laughed dismissively. But then she looked back at Pacifica shyly. “Do you want to…try something?”

“…O-okay,” Pacifica said nervously, but projecting confidence. 

They leaned in toward each other slowly, and Dipper would have slammed the door shut right then, but the kiss only lasted about two seconds before they jerked back, Mabel spluttering and trying to wipe her tongue on her sweater and spitting out fuzz, and Pacifica launching into an aggressive fit of coughing before grabbing a bottle of breath spray from her purse and proceeding to all but inhale the stuff. 

When they had both calmed down, Mabel was the first to speak. “That was really weird. Definitely still into guys, and guys only.”

“Yeah, me too,” Pacifica agreed. “Let’s just pretend that never happened.”

“Pretend what never happened?” Mabel asked innocently.

Pacifica smiled. “I’m sure I don’t know what you’re talking about. Now, pass me those Doritos.”

Dipper carefully closed the door, red-faced, but relieved despite himself that he hadn’t yet found what he was looking for. The next door that he opened was labeled “I did something horrible,” and it turned out to be Mabel cheating on the last question of a math quiz, then immediately feeling so bad about it that she requested to re-take the quiz. The teacher gave her a knowing smile as he put her exam through the shredder and told her she could re-take it in his office the next day after school.  

Dipper was beginning to think that Mabel could never hide something from him as serious as a deal with a demon. Maybe Bill’s sister hadn’t gotten to her yet, maybe she was just circling, making herself known, trying to scare them or draw them out. He was so overwhelmed by his relief, nearly having reached the end of the hallway without finding anything worse than Mabel cheating on that quiz, that he almost walked right past the door whose sign bore a simple a star with one central eye crocheted on a blank background. There was no text accompanying. 

Dipper stopped, his relief immediately turning cold, and backtracked slowly. “ _Bill_ ,” he hissed at the demon peeking through a door a little ways behind and across the hall that he definitely had no business with. “I think this is it.”

Bill was by his side in an instant. “Alexandra,” he whispered, tracing the star with a long finger. Said finger curved into a claw halfway through the motion and sliced through a single stitch before Bill pulled his hand away quickly.

“That’s her name?” Dipper asked. He wasn’t sure why they were whispering, but he wasn’t about to stop.

Bill nodded. “Alexandra Codex. Alexander took his name from her.”

Dipper looked at Bill skeptically. “Codex and Cipher?”

Bill narrowed his gaze at the teen. “I’m good at new discoveries, she’s good at cataloguing. They’re fitting.”

Dipper nodded. He supposed that made as much sense as any of this. He wrapped his hand around the doorknob, but Bill put a hand on his shoulder and he waited. 

“Stay out of the memory,” Bill whispered in his ear. “Keep your feet behind the color line.”

Dipper nodded again, and slowly opened the door. Mabel was walking through the woods not far out from the Shack (they never went far into the woods from the Shack without each other), and all seemed well. She was smiling her usual smile, and the woods were peaceful, no sign of danger stirring between the trees. Perhaps…too peaceful now that Dipper thought about it. There was no sign of _anything_ stirring, and he couldn't hear birdsong or even the whisper of a breeze. 

Mabel slowed her pace to examine what Dipper realized was a falling leaf caught, motionless, in midair. Mabel poked it with a finger, and it barely shifted. Curiously, she looked around, and that was when they both noticed the tree a few paces ahead with a familiar, one-eyed star carved into the trunk. Of course, the star was only familiar to Dipper, not Mabel, and while her curiosity turned to caution, she still began slowly to approach the carved tree. 

A slight frown had replaced her smile and her movements had become a little mechanical, as if she wasn’t quite sure what she was doing or why, but couldn’t bring herself to stop. She reached out a hand as if it were attached to a rising string, and brushed her fingers over the design in the wood. There was a flash of blue, and Mabel leapt back. When the light faded, that very star floated before Mabel, its points and center various shades of pastel yellow, pink, purple, green and orange, its single eye narrowed in examination of the girl in front of it. 

“I’m so glad you came,” the star said, and her voice didn’t echo quite like Bill’s did, but rather seemed to harmonize with itself, its layers forming hauntingly beautiful chords. 

Mabel took another step back, the trancelike look gone from her eyes. “You’re a demon,” she said. 

“You’re a clever girl,” Alexandra responded, and a dimmer, blue glow enveloped her form, before receding to reveal a tall, slender woman in cream-colored pants, a rose pink blouse with a lavender crossover tie, a sea-foam green blazer and tall, high-heeled boots the color of an orange creamsicle. Her hair was long and very nearly white, with faint blue highlights, and an eyepatch in the shape of a star in all of the same colors as her clothes covered her left eye where Bill’s covered his right. While Bill was all hot, arid deserts, this woman was cool, evening skies. In appearances at least, they were complete opposites. 

“Is this better?” Alexandra said. 

“What do you want?” Mabel inquired levelly, obviously deciding, like Dipper would have, that running would be both useless and counterproductive. You don’t run from a mountain lion. 

Alexandra simpered, and Mabel flinched. “Right down to business, then. I like you already,” she said in a voice too warm for the glacial cold of her gaze. “You are a very special girl.”

Mabel wrinkled her nose at the familiar condescending tone. It was the same one Bill had used with them at first, right up until they had saved him from being ripped apart along with the Mindscape by a bunch of cultists. That incident had been nothing if not humbling. Which wasn’t to say that Bill had suddenly stopped being an arrogant asshole most of the time, but his respect for the twins had turned even that side of him oddly endearing. Most of the time. 

There was nothing endearing about the way Alexandra looked down on his sister, but what was even worse was the hungry gleam in her eyes that was something akin to reverence, but far more covetous. Dipper did not like that look at all. 

“You can truly change the world, with my help,” Alexandra continued. “Whatever you want–" at Mabel’s frown, Alexandra quickly changed tack, “–to heal in this ailing world, you could reach out your hand and mend it. With me by your side, your will would be manifest.”

“I like the world the way it is, ailing though it may be,” Mabel said. “I believe we can change it ourselves, without the help of demons.” Her tone wasn’t insulting or aggressive, just earnest, and Dipper was certain his gaze took on a little reverence of its own as he watched his sister talk to the demon with an open heart. 

Alexandra seemed impressed, but not deterred. In fact, she seemed pleased with Mabel’s bravery, and that gleam in her eye sharpened. 

“You do not know your history, then,” she said. “Demons are one of the universe’s most potent mechanisms of change. We are a part of the natural order. And working together with human agents, we have easily turned the tide of human history many times.”

“Then an example of true change would be a human acting on her own to shape history, without the influence – or aid, if that’s what you prefer to call it – of a demon,” Mabel said, unswayed. 

“History, Miss Shooting Star, is easy to change,” Alexandra said, her patience obviously wearing thin as her smile began to show more and more ice-white teeth. “Destiny on the other hand, is another question entirely. You and I are destined for each other. You could say it is written in the stars. And that kind of offer is much more difficult to refuse.”

“Oh yeah?” Mabel said, her own patience straining and her fear beginning to show through. “Watch me.” She turned and began to walk away. Alexandra obviously needed her alive, and if she didn’t make a deal, there was only so much power the demon had over her. 

“If you do not wish to protect the world, then perhaps you at least wish to protect your brother,” Alexandra said sharply, and Mabel stopped. 

“You wouldn’t dare go near my brother,” Mabel said, turning to face the demon again. “He’s already protected.”

“I didn’t say I was what he needed protection from,” Alexandra answered easily. “I know you are referring to the demon Bill Cipher. But what surprises me is that you seem to truly believe he is there to _protect_ your brother.”

“You wouldn’t understand,” Mabel said, but she was less certain than she had been before, and her voice betrayed it. 

“Oh? You think that because I am a demon I do not understand love?” Alexandra said airily. “I did understand it once, and soon after, I understood hate as Bill Cipher, my own brother, destroyed that love and nearly destroyed me as well. It is Bill Cipher who does not understand love, except perhaps the love of fire and blood and ruin. It is in the nature of dreams to be pursued only, and to drive their pursuers to their own demise. He was a wolf at your gate, and you let him inside.”

It took a moment for Mabel to find her voice amidst her surprise and growing worry, but when she did, she said only, “I’m sorry for what he did to you. But Bill has changed.”

Alexandra laughed at that, and there was no humor in it. “The forces of change are never themselves changed. Bill Cipher will be your brother’s ruin, and his ruin will in turn be yours.”

“We’ll take our chances,” Mabel said shakily, turning to leave again. But Alexandra caught her by the wrist and spun her back around. 

“This has nothing to do with chance. This is fate,” the demon hissed, and while she spoke, blue flames ignited and began to engulf their hands. “But don’t worry,” Alexandra continued while Mabel looked down in shock, “you won’t remember a thing.”

Then, Alexandra looked up and met Dipper’s gaze dead-on. Ice shot through his veins as he realized that, in his instinctual desire to protect his sister, he had stepped across the boundary of the memory. 


	7. Close Encounters

The next thing Dipper knew, a pair of hands had gripped him, viselike, around the shoulders and yanked him backwards, and the door to the memory slammed shut. He stumbled back into Bill, and before he could regain his footing, the demon spun him around and shoved him up against the opposite wall. His breath was coming hard and fast, his heart pounding and his blood beating in his ears. He struggled to process what had just happened, and why. 

“That was _incredibly stupid_!” Bill growled, his face suddenly very close, his eye narrowed to a dangerous slit that glowed yellow in the shadowy hallway. “It was a memory. It _already happened_. You couldn’t have done anything to help Shooting Star. You _knew_ that!”

“I– I know, I d-didn’t mean to,” Dipper stuttered, wondering whether he should be more scared of Alexandra or Bill at the moment. “But…it was just a memory! How did she—?”

“Alexandra’s a memory demon,” Bill cut him off. “Nothing is _just_ a memory to her.”

The adrenaline still surging through Dipper’s system had sent his senses into overdrive, and he was very aware of the wall pressing against his back, of Bill’s fingers digging into his shoulders _just_ enough to ache, of their bodies so so close and of Bill’s hot breath ghosting down his neck. Bill’s sharp teeth flashed as he spoke, and that predatory look in his eye was very close to another look that Dipper was very familiar with. His fight or flight response, being denied both options, seemed to be getting creative in coming up with a third. 

_Now is_ not _the time, hormones!_ Dipper mentally reprimanded himself. 

Bill snapped his fingers twice in front of Dipper’s face, bringing him out of his confused thoughts. “Hey, kid! I’m trying to be intimidating here, but the effect is kinda ruined when you’re doing the mental equivalent of drooling down the front of your shirt.”

Dipper flushed, and Bill let out an aggravated sigh, mumbling something about ‘losing his touch’ before he leaned in and captured Dipper’s mouth, saving him from blurting out whatever doubtlessly stupid excuse it had been forming. 

Dipper practically attacked Bill once it was clear that Bill wasn’t _actually_ going to attack _him_. Teeth clashed, distance closed, hands wandered, blood heated and breaths mingled. Dipper had Bill’s lower lip between his teeth, one hand in the demon’s hair, the other under his shirt and vest while Bill’s hands had found their way distinctly further south, when Dipper remembered where they were. 

“Eughhhh,” Dipper moaned, “we’re still in Mabel’s mind.”

Bill laughed quietly, and it was all breath. “I suppose things could have gone much worse. You’re obviously still in full working order, Pine Tree.”

Dipper removed Bill’s hands from his person and slid a little ways out of the demon’s reach. “Yeah, and I probably just scarred my sister’s subconscious,” he said. 

“Nonsense. Shooting Star’s our biggest fan,” Bill said. 

Dipper smiled. “Of course she is.” His smile faltered. “What…happened to her, back there? She didn’t make a deal.”

“Kid,” Bill sighed, reluctantly accepting that this conversation would have to be a serious one, “demons don’t have to make deals. I do it because I’m a gentleman—Don’t laugh, you haven’t met other demons.” He effectively silenced Dipper’s snide remark. “I could just take whatever I wanted. After all, it’s not like anyone could stop me.” 

Dipper bit his lip, his own intention of stopping the demon from going through with his sinister plans for Gravity Falls, whatever they may be, surfacing in his mind. 

“But where’s the fun in that?” Bill went on. “If you’re going to live ’til the end of the universe, you’ve gotta learn to delay gratification. I like playing the long game, and I have the patience of a fucking saint when I have to. My sister, on the other hand, barely knows the meaning of the word. Having to wait for another Alexander must have been awful for her,” he said with a grin.  

Dipper was not amused. Maybe he really was the Queen of England. 

“Anyway,” Bill said, the way he drew out the word expressing his displeasure at Dipper’s killjoy attitude, “forcing a deal like that is possible if the demon’s will is stronger than the human’s, which is almost always the case. It is much easier if both wills are aligned, as they are in a true deal, but a human will can be…inelegantly controlled by a stronger one. It’s not ideal, but it serves well enough for most purposes.”

Dipper nodded understanding. It made sense. But there was still one more thing that was worrying him. “The things Alexandra said about you. They’re not true...right?” Dipper didn’t know why he was asking Bill. What was he going to say? ‘You got me, kid, I’m evil, I’m using you, I’m going to burn this town to the ground and dance on the ashes, oh and by the way, what’s for dinner?’ Dipper could have laughed if it wasn’t so easy to imagine that very sentence coming out of the demon’s mouth. 

“Alexandra’s a demon, kid. She’s persuasive,” Bill said, waving a hand dismissively.

“So are you,” Dipper countered. 

Bill’s gaze turned very sharp and very serious. “I thought we’d gotten past this. You have to trust me.”

Dipper wavered, uncertain what to say. 

Bill growled in frustration. “You can’t let the things my sister says get to you, because they will, if you don’t realize them for what they are: a weapon. Every time she speaks, you have to ask yourself, _why_. This time she was trying to get to Shooting Star, so naturally she used you as leverage. And let’s face it, I’m an easy target. But just think about it. What kind of a stupid ultimate goal is destruction? The pleasure’s temporary, and then you’re left with nothing. Sure, I indulge in a little mayhem every now and then, but I’m a lot more complicated than my sister would paint me. There are many other things I find worth pursuing – you, and whatever this thing is between us, being one of them.”

Dipper began to smile, though not so much because of what Bill had said, but because Bill had seemed _hurt_ that Dipper had questioned his loyalty. Words, as Bill had said himself, were easily manipulated, but feelings – especially for someone as emotionally challenged as Bill – were much more difficult to fake. 

“I trust you,” Dipper said, stopping the demon as he was about to launch into another rant. “Come on, let’s get out of here. I can only think of one productive use of the rest of our time tonight, but I’m not doing it in Mabel’s mind.”

Bill grinned like the cat that ate the canary, and then decided it looked good in yellow. “If you insist,” he said, following Dipper back down the long hallway in the direction from which they’d come. “You know, for the guy dating a demon, I would have thought you’d be more into taboos.”

“I guess you’re just special,” Dipper said, as the world faded out around them. 

☆

“There must be something we can do,” Mabel said, frowning in thought. “What about an exorcism?”

“Whoa, kid, careful how you throw around the E-word,” Bill said, stepping back. 

They had told Mabel what they had done last night (well, half of it), and while she’d been upset at first that they had gone digging in the darkest corners of her mind without telling her, she had felt guilty enough about being swayed by a demon to conceal, for reasons she couldn’t explain, an encounter that she still couldn’t remember, that their trespasses more or less evened out. Now, they were all concerned about removing the demon’s influence from her before things got worse. Bill now suspected that the blank patches in Mabel’s memory were collateral damage caused by her subconsciously fighting against Alexandra’s hold, but the demon was only getting stronger the longer she was bound to Mabel. 

“Would an exorcism even work?” Dipper asked. 

Bill cringed. “It might, if you use a good one, but it’s very risky. I won’t be able to be present for obvious reasons, and I can’t say what my sister will do when she feels threatened.”

“Well she knows we're onto her now, so we have to do something quickly. Do you have a better idea?” Mabel asked. She was also, understandably, peeved that she was being used to settle an old sibling rivalry between demons. 

“Not as such,” Bill ground out. 

“I don’t see that we have much of a choice, then,” Dipper said solemnly. “But Mabel does. It’s your decision, Sis. What do you want to do?”

She fixed him with a serious look. “Will you still love me if my head spins around and I start spewing green vomit all over you?”

Dipper chuckled as Bill sighed theatrically. “That’s not how possession works,” the demon muttered.

“Of course I will,” Dipper said, returning Mabel's mock-seriousness with the genuine article. “No matter what.”

“Fine!” Bill said, throwing up his hands. “I’ll get you a real exorcism, only because you two noodlebrains might try to pull something out of a Hollywood movie on your own. Hell, I’ll get you the damn nuclear warhead of exorcisms! You’ll need it. Just…let me prepare you properly, and _don’t_ go off-script. Capisce?”

Dipper and Mabel both nodded once dumbly at Bill’s outburst. 

“Then wait for me,” Bill ordered. Then he disappeared. 

Mabel blinked. “Do you think he’s really going to trust us with something that could hurt him?”

It was an interesting question. Dipper was dying to know the answer. 


	8. Exorcism For Dummies™

Bill Cipher could not believe what he was doing. The fact that he was certifiably insane was not news to him – in fact, he was usually the first to inform his unsuspecting victims- er, _contractors_ of the fact. But this was something else entirely. Could he really be about to hand over serious ammunition against him to two humans? Two humans who already knew too much?

Of course, he needed his sister out of the picture again as much as they did. He hadn't considered an exorcism before because he couldn't perform one. But now he had two willing humans to do it for him. The problem was, the exorcism they would need to bend his sister to their command could bend him just the same. The problem was also that Pine Tree might be hurt or killed, and Bill would not be there to prevent it. Even if Shooting Star were the one who got hurt directly, Pine Tree would still bleed. 

The problem was that he had stopped thinking solely about himself. He had, in a way, already trusted Pine Tree with even greater ammunition against him if the kid was smart enough to use it. Or if someone else was. 

He had a hunch that he knew why his sister had waited so long. 

His fingers stopped skimming the old, dusty books near the top of the floor-to-ceiling bookshelf (he was currently floating about thirty feet above the ground) to rest on an enormous black leather-bound tome. Its spine was bare, but when he pulled it out, the cover was just as he remembered it: embossed in silver in a language now known only to him and a few reclusive linguistic historians. 

How he had ever let this one get away from him, he still wasn't certain. Suffice it to say that the crusaders had been more competent than history typically gave them credit for. He had been meaning to track it down again for a few centuries now, but he had just never gotten around to it. He was a busy guy. Of course, he had planned to burn it when he did get his hands on it, not deliver it into the hands of an ex-nemesis-turned-lover, and wasn't that a volatile combination now that Bill thought about it.

He sneered down at the heavy volume in his hands (though not heavy to him of course), blue flames licking his fingertips but not so much as singeing the leather. He would destroy this book, but he needed it first. With a quiet noise of displeasure, he disappeared, the dark and dank room never really having registered his presence.

☆

Mabel and Dipper were just finishing breakfast with Grunkle Stan when an enormous old book dropped out of the air and slammed to the tabletop, rattling their cereal bowls and nearly spilling their drinks. 

"Page five-hundred sixty-seven."

Slowly, the twins looked up to see Bill hovering above the table, looking distinctly unhappy. 

"And if you value your internal organs you will _not_ start reading it aloud."  

Dipper’s hands shifted to his stomach protectively. Grunkle Stan finally looked up from his paper at the demon hovering over the table. Bill batted his eyelashes and gave him a flowery little wave. 

Grunkle Stan returned a markedly less friendly gesture. “What’s all this about?” he grunted to Dipper. 

“Uh, research project!” Dipper replied quickly, hefting the book in his arms with significant effort. 

His Grunkle had a right to know what was going on, but Dipper knew he would only complicate things. He wouldn’t allow them to go through with one of Bill’s plans, especially when it involved their safety, even if it was the best option, and even if Bill would be the first to testify that it hadn’t been his idea. Stan still didn’t trust Bill; he only put up with the demon because he made Dipper happy and didn’t seem to pose an immediate threat to anything other than their tolerance for strange and annoying behavior. The obscene amounts of gold that Bill was overpaying as rent didn’t hurt either. But Dipper knew that, though he didn’t show it in the obvious ways, Grunkle Stan cared about him and Mabel more than anything, and would do anything he could to protect them. Even if the danger he thought he was protecting them from was, in the immortal words of Princess Leia, their only hope. 

“It’s summer,” Grunkle Stan said suspiciously. 

“Yeah, I’m doing it for fun,” Dipper said. “You know me, total nerd.” 

Bill snorted from above, though whether it was because Dipper was a terrible liar, or because that part was true, he couldn’t tell. 

Luckily, Bill stepped in (literally, stepping down onto the center of the table). “Sorry Mr. Pines, but I’ve gotta borrow the kids. For research!”

Stan looked alarmed and opened his mouth to say something, but the next second Dipper and Mabel found themselves in the middle of the woods in a flash of blue light. 

“Smooth, Bill,” Mabel commented. 

“Grunkle Stan’s going to think you’re experimenting on us,” Dipper groaned. 

“Still better than the truth, isn’t it?” Bill said, straightening his cuffs. “Let’s get to work before I change my mind.”

“Where did you get this book?” Dipper asked warily, flipping through the pages. It was very old, some of it written in languages that he didn’t even recognize. Luckily, page 567 was in good old Latin, albeit a little older than Dipper was used to reading. 

“Checked it out of the Vatican’s secret library,” Bill said, holding out his hand over the ground  and scorching an elaborate magic circle into the earth with blue flame. 

“And by ‘checked out’ you mean…?” Dipper said. 

“Borrowed,” Bill said, inscribing a five-pointed star into the circle by tracing his finger in the air. 

“And by ‘borrowed’ you mean…?” Mabel said. 

“Stole,” Bill said happily, finishing his design. Dipper noticed how he took care to stay outside of it himself. "They won't miss it – they didn't even know what they had.  I also stole these for you, Pine Tree.” Bill waved a hand through the air and was suddenly holding up a full set of black clerical vestments, complete with white collar.

“I can’t wear those,” Dipper said, frowning. “I’m not a priest.”

“It’s all about the symbols, Pine Tree,” Bill said. “Besides, they suit you.” 

Before Dipper could ask how he could possibly know that, with a snap of Bill’s fingers he found that, counter to what he’d said, he could in fact wear the garments. He looked down in numb surprise at the long, black coat and pulled a little at the stiff, white collar. 

“What did you do with my clothes?” Dipper asked, meeting the demon’s eye that had been roving a little too appreciatively over his new appearance. 

“It was very tempting to teleport those boring things you call clothes over the mouth of an active volcano,” Bill said, “but they’re on your bed in your room. I even folded them. Am I the best boyfriend ever or what?”

“Yeah, sure,” Dipper sighed. “What else do we need? A bell and a candle?”

“Don’t be ridiculous,” Bill said, rolling his eye. “I’m afraid I’ve gotta put you into a bit of a bind, Shooting Star.”

“Do what you must,” she sighed dramatically. 

Bill waved a gloved hand and a ten-foot, five-pointed star made, seemingly, of blue light, appeared behind Mabel. There was an open, glowing shackle on each arm of the star, and Mabel yelped as she was raised several feet into the air with the star and the shackles closed around her ankles, wrists and neck. 

The hairs on the back of Dipper’s neck stood, and he shot Bill a look. Still, he stayed put beside the demon, waiting for what would come next. When it occurred to him that he had been waiting a rather long time, he looked over to see that Bill had lapsed into a rare mood of thoughtfulness and concern. Those always made Dipper nervous. When Bill had to take something seriously, it was something very serious indeed. 

“Do you remember when I told you two that I would never teach you anything powerful enough to use against me, because nothing that powerful existed?” Bill finally said.  

Mabel and Dipper nodded (Mabel as best she could). “Although,” Dipper said, looking down at the book in his hands, “this exorcism kind of proves that wrong, doesn’t it?”

“There’s another thing,” Bill said, seemingly unfazed by being called out on his lie. “It’s a kind of shield, way more powerful than the one I taught you then. It will keep my sister out of your head, Pine Tree — sorry, Shooting Star, she’s already in your head, so it wouldn't do you any good.”

Mabel shrugged from up on the magic star.

“But it will keep me out, too,” Bill continued. “If you call for help, I won’t be able to hear you or know where you are unless you break the shield. And if you do, Alexandra will be able to get at you just as quickly as I will.”

“I understand,” Dipper said quietly, looking up at the demon. “How do I do it?”

Bill rolled his eye again. “ _You_ don’t.” 

He took Dipper’s head in his hands, and Dipper saw white. Then he saw two triangles come together to form a star, rather like the Star of David, but tilted 90 degrees. When the whiteness cleared, the star remained burned across his vision. When Dipper met Bill’s eye again and registered his expression, he realized the demon looked perturbed, staring into Dipper’s eyes with a frown. 

“What’s wrong?” Dipper asked worriedly. What if Bill had messed up something in his mind? He was already beginning to imagine the possibilities: being able to taste only carrots for the rest of his life no matter what he ate, losing the ability to see one of the colors in the visible spectrum and not even remembering what it looked like, a split personality that only surfaced in retro American diners—

“It works,” Bill said, cutting off Dipper’s spiraling thoughts. “Shooting Star’s bindings won’t last long without me here to maintain them,” Bill continued over Dipper’s sigh of relief, “so I suggest you read quickly and stop for nothing less than the Devil himself.”

Dipper swallowed thickly. “That’s an expression, right? The Devil doesn’t really exist.”

Bill smiled. “Are you kidding? The guy owes me money.”

“I…really can’t tell if you’re joking,” Dipper said. 

“Kid, that’s what makes it so much fun,” Bill said with a more genuine smile. “There’s just one more thing before I leave.”

Bill, who still had Dipper’s head in his hands, leaned down and pressed his lips to Dipper’s surprisingly gently. It was Dipper who locked his arms behind Bill’s neck and demanded more, which Bill gladly gave. 

“See you after the show, kid,” Bill murmured in his ear.

And then he was gone.


	9. Lost Things

Dipper, who was now feeling much more nervous without Bill by his side, quickly opened the enormous Medieval tome and turned to page 567, which, for the record, was not even halfway through the book. He mouthed the first few words silently just to be sure he wouldn’t mess up the archaic pronunciation, then looked back up at his sister, who was watching him with a patient confidence that was reassuring despite it being obviously mustered for Dipper’s benefit. 

“You ready, Mabel?” Dipper called. 

“Go for it, Brobro,” she answered, giving her best thumbs-up in light of the tight shackles of demonic energy around her wrists. 

Without further delay, Dipper began to read the words aloud as fast as he knew he could without stumbling over them. Though his twin sister bound at the neck and limbs in midair by demonic restraints – virtually being crucified – was a sight that distressed Dipper greatly, his twin sister half-possessed by an obscenely powerful demon _without_ restraints would be even more distressing. He needed to complete the incantation before Bill’s magic wore off. 

Mabel seemed okay, until she didn’t. When Dipper was about a third of the way down the page, glancing up quickly every so often to check on her, he noticed her encouraging smile had turned to a pained grimace. He nearly stopped reading to ask if she was okay, but if he was being honest with himself, he had expected this process might be painful, and the best thing he could do was get it over with as quickly as possible. He’d be doing Mabel no favors by giving Alexandra time to think. At least the exorcism seemed to be working. 

The next time he looked up was when Mabel let out a quiet, high-pitched whine that tapered off into what almost sounded like a hiss for a second at the end. Her eyes were starting to glow faintly blue. Dipper sped up the pace just a little bit more. 

Mabel was soon whining out with each breath, and writhing slowly against her restraints. Her eyes were closed now, but Dipper could see the blue light leaking out from beneath her eyelashes. She looked…sick. Dipper wished he’d thought to ask Bill how she _should_ look. 

As that thought crossed his mind, he hit a word that made him falter. _Providentia_. He hadn’t been bothering to translate in his head the words he was reading aloud; it would have slowed him down. But what did exorcising a demon have to do with providence? Suddenly, he wondered just what it was he’d been reading, and if it was an exorcism at all. He remembered what Bill had said of Alexandra’s plan to kill him before he’d banished her. She was going to try to lock him in the mindscape of a single mortal, and then kill his unwitting jailor. And if there was a chance that would have worked on Bill, then there was a chance it would work on his sister. Perhaps that chance was even greater if the mortal was the one to which Alexandra was already linked by providence. 

But surely Bill wouldn’t…? No, the question Dipper should be asking himself was, was he willing to bet Mabel’s life that he wouldn’t? 

☆

Mabel, whose thoughts had become a blur amidst the pain and the heavy haze of magic, suddenly remembered a white-gloved hand, and a melodic voice saying, _“Mind if I cut in?”_ Then the memory cut out, as did everything else. 

☆

There was a soft chuckle, and Dipper’s eyes shot back up from the book to his sister. She was looking down at him with slitted pupils set into pale blue irises. He recognized those eyes, and they chilled him now just as much as the last time he’d seen them. He had stopped reading more than a minute ago.

“Hello again, Mister Pine Tree,” Alexandra said, her cool, harmonic voice spilling wrong and alien from Mabel’s lips. 

Dipper could’t bring himself to keep reading whatever it was he held in his hands, and he knew Alexandra could tell. He was cornered. 

“You are right not to trust Bill Cipher,” she said, her tone sharp but her pace languid. She knew she could take her time. “Even if he does love you, do you really think he would choose to save your sister when he’s finally presented with the opportunity to get rid of his own?”

Dipper had thought that he was finally done doubting Bill, that – against all odds, common sense and primal instinct – he really could trust the demon. But now, when Bill had so much to gain and Dipper had so much to lose, he just wasn’t certain enough. 

Still, that didn’t mean he trusted Alexandra in the slightest. “Bill’s a demon, he doesn’t love me. He thinks I’m interesting.” He didn’t need to give Alexandra any more leverage than she held already. 

“Do not presume to lecture me on the nature of my own kind, _boy_ ,” Alexandra spat, and Dipper had never seen Mabel’s face contort in such _wrath_ before. “Love is very powerful for a demon, precisely because it is so rare. But hatred to us is like breathing, and you represent a dalliance of a century at most, while I represent a threat to his life and his place in the grand scheme. Bill has his priorities, of which he is always the first.”

“Maybe that’s true,” Dipper said with false calm, while all he could think was _Mabel, Mabel, Mabel, please!_ “What’s your point?”

Her eyes narrowed. “That isn’t a star pun, is it?”

“No!” Dipper said, throwing his arms up in exasperation. “God, you two really are siblings.”

“Well then,” she said calmly, “I suppose my point is, I could send his love up in flames like he did mine, just to burn my brother in a flare of particularly poetic justice…”

Dipper yelped and leapt back when blue flames sprung to life at his feet and quickly engulfed him, only to realize that they didn’t burn. 

“…but that would be petty, and it would not get me what I want.” The flames dissipated. 

Dipper took a deep breath, willing his heart rate to slow after his near spontaneous immolation. “What do you want? And if you say Mabel, I can tell you now that you’ll have to burn me to ashes before I let you have her.”

“If your sister had but accepted me, I could have been back in the Mindscape by now and she would have had no further involvement,” Alexandra said. “But as things stand, there is only one way I can reenter the Mindscape, so what I want is for you to break that ridiculous shield around your mind and call for our mutual acquaintance. What I want, Mister Pine Tree, are the powers he robbed me of, and then I want Bill Cipher begging on his knees for my mercy.”

“Because that’s not petty,” Dipper replied, stupidly stubborn as always. He didn’t believe for a second that Alexandra had any intention of letting Mabel go if she was so special, but the situation was quickly slipping from his grasp. He had no idea what to believe, and it seemed like Bill was the only one who would have any idea what to do. He could only hope that Alexandra couldn’t sense it somehow when he concentrated on the star burned into his mind’s eye and carefully pulled the triangles apart, dismantling it. _'Bill,’_ he thought, at the mental equivalent of a whisper. 

“It’s fair,” Alexandra was saying. “And because I'm being fair, I will even return something he took from _you_. Your memories.” She grinned, and her teeth – Mabel’s teeth – were sharper than daggers. 

The moment after Dipper dropped the shield, his mind was flooded with images, like a rapid film reel being fed behind his eyes. He saw Bill invade Grunkle Stan’s mind in order to place the deed to the Mystery Shack in Gideon’s hands so that he could build a theme park on top of it, and then he saw Bill rage nightmares against him and Mabel and Soos when he failed, for reasons Dipper had suspected had nothing to do with Gideon or the Mystery Shack. He saw Bill hold out his hand, wreathed in blue flame, while the red timer on McGucket’s laptop counted down its final seconds, before he pulled Dipper out of his body and laughed while he used it to smash the laptop with all of the secrets it contained. He saw Bill slide forks into his flesh, the pain of which he had felt in full after he had taken his body back. But before that night in the hospital, he saw Bill, still in his body, laughing at him through the window of the car with Wendy and Soos as they drove off, leaving Dipper behind, helpless. And then Bill had fought with Mabel to get to the journal to destroy it as well. Dipper remembered the feeling of eyes – or rather, an eye – on his back nearly every day after that, and the fear of a triangular shadow he would see out of the corner of his eye when he was alone. Finally, he remembered every single person in Gravity Falls, ending with Soos, Wendy, Grunkle Stan and Mabel looking back at him with yellow, slitted eyes and laughing when he tried to shake them out of it in tears, before Bill finally came to him, grinning, with a deal: _“How about I put you out of your misery, Pine Tree?”_   He remembered telling Bill,  _“You’re a vile creature and I hate you,”_ and meaning it with all of his heart. He remembered kissing Bill with all of the burning passion of that hatred, and then he remembered a nothingness he could only liken to what he imagined death was like. In short, he remembered it all. 

And then he blinked, and he was back in the woods, and Bill was beside him. 


	10. Family Reunion

“Done already—?” Bill’s usual smile turned immediately to a scowl when he took in the scene. His restraints had broken seconds before he’d arrived, and Alexandra now stood before them, brushing herself off from the short drop to the ground. “Oh. Hello, Alexandra,” he said, his tone too calm and even, like a wire pulled tight enough to cut. 

Without ever turning away from his sister, Bill quickly glanced over Dipper and reached out a hand. “Did she hurt you at all?” he hissed under his breath. 

Dipper flinched and recoiled from Bill’s reach. He felt horrified with himself, but he couldn’t help it – it was instinct, he remembered that now. None of his newly reacquired memories were new information to him; Bill had told him everything that had happened between them in the years before. But it was different remembering it happen to him, feeling all of that anger and fear. He had considered Bill a monster in every sense of the word. He now had two very different understandings of the man beside him, and he just couldn’t reconcile them. 

Bill frowned at Dipper’s reaction. “Pine Tree?” he said, allowing more of his focus to fall on the teen. 

Dipper couldn’t find his voice, could barely meet Bill’s eye for a second before having to look away. It was enough. Bill’s eye widened, and he whipped back to turn his full attention on his sister. 

“You fucking bitch!” he screeched. “How dare you—“ 

“Return to the boy what was his?” Alexandra cut in cooly. “What you stole from him?”

Blue fire sparked and skittered along Bill’s fingertips, which were twitching and lengthening into claws. “I tried to give him back what I could,” he growled, obviously wrestling with his urge to leap at Alexandra and rip her to shreds. Because it was Mabel he was facing, too. 

Dipper, who was beginning to feel strangely calm and distant from the scene – perhaps that was what shock felt like, he mused vaguely – took note of Bill’s restraint. Surely a monster would have no qualms about tearing a girl apart to get at what was inside?  

“Yes, you aren’t as skilled with memories as I am,” Alexandra said. “You can fill his head with all of the fantasies you can concoct, but when it comes to reality, you’re at a bit of a loss.”

“You always did resent me because my talents were more fun,” Bill replied. “What’s your move here, Alexandra? Other than pissing me off, I mean. You still aren’t nearly powerful enough to get back into the Mindscape.”

“I’m not,” she admitted, and it seemed to visibly pain her. “But you are.”

Bill laughed coldly. “My dear sister, are you expecting me to just invite you back home?” 

Alexandra shrugged. “More or less. Shall I tell you why?”

“Enlighten me, please,” Bill said.   

“Because you love him. And he loves her. I learned this one from you,” she said with a wicked smile, before manifesting a silver fork in her hand and driving the sharp tines deep into Mabel’s forearm.  

_“Mabel!”_ Dipper screamed, reality suddenly crashing back down around him. 

Bill’s hands curled into fists, his claws digging through his gloves into the flesh of his palms as his gaze flickered to Dipper again, but he remained still. If he tried to restrain Alexandra physically, she would begin rending Shooting Star's mind instead, and the damage would be much more difficult to repair.

“Stop it, Alexandra!” Dipper begged. “You said yourself Bill’s first priority is always himself. This isn’t going to work!”

“Why do you keep listening to her after I told you not to?” Bill growled at Dipper. “Do I need to spell it out for you, Pine Tree? My sister is a lying, manipulative, evil serpent.”

Alexandra pulled the fork steadily down the length of Mabel’s arm, rending the flesh in four deep, even tracks. Blood began immediately to slip down the grooves and drip from the tips of her fingers. Dipper even caught a glimpse of bone before it was subsumed in red. “Oh, I think it’s working,” she said. 

“You’re not going to destroy your best shot at getting back into the Mindscape for a hundred years,” Bill said defiantly.

“Providence works in strange ways,” Alexandra said, holding the bloodied fork up in front of her face to examine it, turning it slowly until the tines pointed towards her. “Perhaps maiming this girl until the brink of death is exactly how I get back to the Mindscape.” She plunged the fork into Mabel’s cheek and ran it down to her jaw, more quickly this time. “Shall I take an eye next?” she asked, holding up the fork again. “It would be kind of funny." 

“Please, stop,” Dipper gasped, tears now streaming down his face. When he met nothing but cool ice in Alexandra’s borrowed eyes, he turned to Bill. In his eye, Dipper saw fire. “Do something,” he pleaded, barely above a whisper. 

Bill growled low in his throat and the blue flames engulfed his hands completely, licking up his arms all the way to the elbow. All color began to leech from the forest from the sky down, descending like a curtain.  

 ** _Keep reading, Pine Tree._** Dipper heard Bill’s voice immediately in his head, though the demon didn’t take his eyes off of Alexandra, who was looking around with a triumphant smile.  

_‘What was I reading?’_ Dipper thought back sharply. _‘It isn’t an exorcism, is it?’_

Alexandra inhaled deeply, and exhaled slowly, as if savoring the air, before she said, “I think I’ll keep Miss Shooting Star after all. While she is my vessel, you can’t touch me, brother.” 

**_There isn’t time for you not to trust me this time!_** Bill sounded angry, but also hurt, like the last time Dipper had doubted him. **_I needed something more powerful than an exorcism. What you hold in your hands is a weapon specific to me and my sister. It won’t hurt Shooting Star, but it will hurt Alexandra, and it will hurt me. Hopefully her more than me, in the state she’s in. It will definitely weaken her enough that she’ll have to relinquish her hold on your sister._**  

 _‘Why didn’t you tell me all that to begin with?’_ Dipper asked.   

**_Because it’s difficult to trust someone who doesn’t trust me! But I gave it to you anyway, because I love you, you infuriating idiotic mortal!_ **

Bill was looking right at Dipper now, furious and terrifying, but also…terrified. More scared and unguarded than Dipper had ever seen him. And right now, that was really not a good thing. 

“It took much longer for the humans to rub off on you than it did me,” Alexandra went on. “But I had a feeling it was only a matter of time. I knew your curiosity. And now you’ve finally grown attached.” She took a step towards them. “Weak.” Another. “Vulnerable.” Her eyes flicked to Dipper and his blood froze.  

“Big mistake, Pointy,” Bill growled. “No one threatens Pine Tree but me.” **_Now or never, kid!_**  

Bill threw up a shield of blue-tinted energy around himself and Dipper a split-second before Alexandra brought knife-sharp sheets of the same energy crashing down over it. Dipper’s eyes skittered frantically over the page to find where he’d left off, and he stuttered a few times on the first word before he finally picked up a rhythm and continued reading the incantation at a yell. He tried to tune everything else out as he read, as Alexandra continued her onslaught and as Bill struggled to hold up against it. Dipper picked up the pace even more, and then he was tuning out hisses of discomfort that quickly turned into screams of agony as Alexandra crumpled and began to claw desperately at the flickering shield that Bill was just barely maintaining, having fallen to his hands and knees beside Dipper.  

Just a few more verses. Dipper pleaded silently with Bill to hold on. Alexandra was already face-down and unmoving in the grey dirt, but the shield was now gone completely and Bill’s breaths were coming shallow between his screams. He hissed what was clearly a string of obscenities, despite them being in languages Dipper suspected weren't even human, his claws lengthening and digging into the dirt before he collapsed and fell silent like his sister. 

Dipper finished the last words of the incantation and dropped the book at his feet. Moments later Mabel’s body began to glow blue, and then that glow became a shine as bright as a star, and Dipper had to cover his eyes with his arm. When the light dissipated, there were two bodies beside one another, his sister’s, and that of the woman he’d seen in the woods in her memory. Alexandra.  

Dipper wanted to run to Mabel, but he knew they were not out of the woods yet, literally or metaphorically. So he did what he second most wanted to do, and dropped to his knees beside Bill, shaking his shoulders and whispering, _“Wake up!”_ over and over in his ear. 

Dipper was relieved when Bill whined and rolled over onto his back, before he saw what looked like a crack down the side of Bill’s face, spilling blue light. Bill opened his eye, and it was worryingly dull in contrast – not its usual warm, glowing gold, but a pale, sickly yellow. He squinted up at Dipper almost as though Dipper was a dream.  

“Bill, are you alright?” Dipper asked, wanting to give Bill some physical gesture of comfort, but finding himself once again shying away from contact with the demon.  

“Jeez, Pine Tree, you and books really are a dangerous combination,” Bill groaned, and blue light leaked from his mouth and between his teeth. 

“Bill, I think Alexandra’s waking up,” Dipper said, looking over his shoulder at the other demon and seeing her stir. Now that he was really looking, he could see that every inch of her skin was latticed with fine cracks like the one across Bill’s face, making it look like her veins were filled with light. 

“Stay here,” Bill said as he pushed himself slowly, painfully to his feet. He ripped off his eyepatch as he did so, and Dipper caught a glimpse of what was beneath before Bill turned his back.  

He had never seen Bill in human form without his eyepatch before, and he couldn’t quite say what it was he saw then. He _felt_ it more than saw it. It was…infinite. Possibility. Doom. Eternity. And he knew that if he looked for more than a second, he would go insane. Dipper quickly cast his eyes down and made a point of not looking higher than Bill’s shoulders as he watched the demon walk away.   

Bill clutched at his side and limped slightly as he approached his sister, and Dipper could only assume there were more cracks of light beneath his clothes. Alexandra opened her eye and took in her position immediately, her fingers lengthening into claws, but instead of attacking Bill, she went for Mabel, still unconscious beside her.  

Bill shot his hand out to cast a weak, flickering shield around Mabel, and that was when Alexandra sent her own eyepatch up in flames and hissed something in a language that sounded in no way human, then threw a complicated pattern of shining energy at Bill.  

Bill had no chance of dodging or deflecting, but when it crashed into him it seemed to slice right through him, and then he just…disappeared. The color came back into the world immediately after, too bright. They were no longer in the Mindscape. Meanwhile, Alexandra had collapsed again, panting from the effort of the spell. 

Suddenly, Dipper had a splitting headache. _“Fuck!”_ he hissed, clutching at the sides of his head and rocking with the waves of pain.   

**_Pine Tree._ **

_‘Bill, where are you?’_ Dipper only just managed to string the coherent thought together. 

**_Take a wild guess!_ **

“Ow! Don’t yell!” Dipper hissed. _‘Oh…shit.’_  


	11. Sharing

_‘She trapped you in my mindscape, didn’t she?’_ Dipper thought, beginning to panic.  

**_Gold star, kid. Listen, that spell took a lot out of her, but she’ll recover enough any minute now to finish the job. She’s going to kill you, and I just might join you when she does. The only way we can keep that from happening is if you give me control. Now._ **

Memories of the last time Bill had taken control of his body surfaced automatically, still painfully fresh and new when the years should have dulled them. It had been by far the most terrifying experience of his life, watching his body become Bill’s puppet. And something told him it would be even worse from the inside. 

**_Pine Tree, I would apologize for that if we had the time, but we don’t. What I can do is promise I won’t hurt anyone but Alexandra when I take over._ **

Meanwhile Alexandra was pushing herself up from her hands and knees, and she held out a hand, blue fire sparking in her palm but guttering out almost immediately.  “Well,” she breathed, “I don’t need magic to kill a human.” 

Though her gait lurched from her injuries, she began advancing toward Dipper quickly, and Dipper scrambled in the dirt to back away. 

_‘Okay, okay! How do I do it?’_ As much as the idea of Bill in control of his body terrified him, the prospect of getting sliced to pieces by the scythe-like claws Alexandra was holding at her sides as she stalked closer was even less appealing. He could see which was the lesser of the two evils at the moment. 

**_Just try to clear your mind. I’m right here. All you’ve gotta do is let me in._  **

Dipper thought “clearing his mind” was much easier said than done as he backed away from certain death in demon form, never turning his back on her, but never looking her in the eye. However, having his life on the line was excellent motivation. He took a deep, shaky breath, and tried to concentrate on nothing at all. 

He was vaguely aware that his feet had stopped moving, and when he looked up again, Alexandra was right in front of him. But as her clawed hands descended to slash his throat, his own hands shot out and grabbed her wrists with a strength he knew he didn’t have, and held them steady in the air. Then, slowly, he bent them backwards, and she let out an inhuman screech of pain. 

Finally, he looked up into her eyes, and despite Dipper’s instincts screaming at him to look away, he held her gaze, and her eyes widened in fear. Though Dipper’s mind still couldn’t process what he saw in her uncovered eye, he supposed he was safe from the sight this time. Bill was, after all, already insane. 

“Goodbye, sister,” he heard himself say. But it was not his voice; it was Bill’s. 

“Wait!” Alexandra cried. 

But Dipper could feel his eyes burning with light and his blood raging with magic, and his fingers were digging into Alexandra’s flesh between the cracks of light. Then, he began to pull. 

She screamed again, a terrible, piercingly high sound that broke off only when her body split apart and burst into a billion shards in a blast of blue light. A second later, what sounded like hundreds of screams from some kind of animal echoed through the trees around them, before everything fell silent. 

_‘Bill?’_ he dared to break the silence (sort of) after what felt like a painfully long time. He felt drained and exhausted and pained to the core, but he guessed that the feeling belonged more to Bill than him.

**_It’s done._**  

 _‘How?’_ Dipper asked. 

**_I couldn’t trap her in a human’s mindscape, so I scattered her into the minds of all of the deer in northern Oregon, and then killed them all._ **

_‘The…deer. Okay. That explains that…horrible sound. Mabel’s gonna—_ Mabel! _’_ Dipper began to panic, unable to see her until Bill turned his head.  

She was still lying face-down on the ground, but she was making pained noises and starting to move, slowly. 

**_Pine Tree, I know the last thing you want me to do right now is lay a hand on your sister, but I can heal her._ **

_‘Do it,’_ Dipper replied immediately. 

He could only watch from behind his own eyes as Bill slowly and deliberately approached Mabel, being careful not to appear hostile, Dipper realized. He knelt down in front of her and she looked up, wincing as she tried to push back onto her knees. The left side of her face was smeared and dripping red. 

“Dipper,” she breathed, relief mingling with the pain in her voice. But the relief quickly turned to fear when her eyes met his. “Bill?” she said, shying back.

“Got it in two,” Bill said. “Not bad, Shooting Star.” 

“What…what happened? Is Dipper…?” Her voice took on a sharp edge of anger and suspicion, and something threatening moved in her eyes.  

_‘Let me talk to her! Can I do that?’_ Dipper couldn’t bear to have his sister look at him like that. 

**_You can._ **

“Mabel, I’m here,” he said, and his voice was his own. Experimentally, he reached out a hand, relieved when it responded to his command, and placed it gently on Mabel’s uninjured cheek. “It’s okay,” he said as more tears began to fall from Mabel’s eyes and mingle with the blood on her face. “Just let Bill heal you, and then we’ll explain everything you missed.”

Mabel nodded, and Dipper took a mental step back, allowing Bill to take control again. He kept his hand on Mabel’s cheek, and his palm began to glow a soft blue. In seconds, Mabel’s wounds knit themselves back together, leaving only drying blood with no scars underneath. 

Mabel could remember nothing after losing consciousness in her bindings, and Dipper, who now felt somewhat light-headed from the latest magic expenditure (apparently his and Bill’s feelings were sympathetic while they were like this – whatever one felt, the other did, too), let Bill explain most of what had happened, as he understood it better anyway. 

“And now, Pine Tree’s stuck with me until Alexandra’s seals wear off,” Bill finished. “She was weak when she cast them, so it should only be a few hours.” 

Dipper mentally groaned. He wasn’t sure he could take a few more hours of this dull, deep pain and emptiness, let alone continuing to share his body with the demon he really just needed some distance from for a little while. 

“And I feel like crap because Bill feels like crap—“

“Hey, speak for yourself, kid. I can take a beating pretty well,” Bill interrupted him, making him look absolutely insane. 

“…Anyway,” he continued, “I vote we go back home and crash. I really don’t want to deal with –” he gestured to himself “– this.”

“Sounds good, Brobro,” Mabel said, and hugged him. “I’m just glad everyone’s okay.”

“Except for the deer!” Bill piped up. “But those guys breed like rabbits, they’ll be back in these parts soon.”

“Shh, Bill,” Mabel said. “I’m hugging Dipper. I’ll let him deal with you later, but I’m still not happy about the deer.”

“I could resurrect them as zombie deer,” Bill offered. 

“Shh!” Mabel said again. 

And then Dipper was hugging her back. When they finally let go of each other, they turned in what they thought was the direction of the Mystery Shack and began to walk home. But after the first step Bill took control again and turned around. 

“One last thing,” he said, walking back into the clearing and picking up the enormous, old tome that Dipper had, surprisingly, forgotten all about. It didn’t feel heavy at all this time. 

Bill snapped his fingers, and when nothing happened he complained, “Why are you humans so terrible at magic?” before sighing and muttering a few words in a language Dipper didn’t recognize. 

Dipper gasped and tried to drop the book when it went up in blue flames, but Bill held onto it firmly, and it didn’t burn his hands. Soon, Dipper was merely whining mentally as he watched all that arcane knowledge burn to ashes in his own hands. 

“That thing was too dangerous,” Bill said, letting the ashes sift down through his fingers. 

_‘For you or for me?’_ Dipper asked. 

**_For both of us. Some of the things in that book man had no business ever knowing. They are best forgotten._ **

_‘See, when you say things like that, it just makes me want to know more,’_ Dipper sighed. 

**_That’s why I like you, kid._ **

Then Dipper was back in control again, and as he walked back to rejoin Mabel, he smiled. It was weak, and small, but it was the first time he had done so since they had started this whole thing in the woods. 

“Hey Bill,” Dipper said, aloud for Mabel’s benefit, “how come the two times you’ve possessed me, I somehow ended up in a priest outfit?” 

“It’s a mystery of the universe,” Bill said. “What I can tell you is that you’re walking in the complete opposite direction of the Shack.”


	12. Promises

**Notes for the Chapter:**

> Cool note about this chapter: I wrote it in Ashland, Oregon under a full moon that looked blood-red due to all the smoke in the air from the forest fires.

Dipper was so physically and emotionally exhausted that he didn’t mind when Bill occasionally took over to keep them heading in the right direction. It was almost…relaxing, if he didn’t think about it too much. He was able to stop worrying so much about Mabel when it became clear that she truly remembered nothing from when she was under Alexandra’s control, and that she was only in pain from the time she woke up on the ground until Bill healed her a few minutes later. 

They passed two deer carcasses before they got back to the Mystery Shack, their wide eyes and gaping mouths rimmed with drying blood. Mabel shot Bill a dirty look when they reached the second, except it was Dipper at that point, and he just sighed in sympathy. In his book, Mabel was easily worth all the deer in the world and more. He couldn’t be anything but grateful for what Bill had done. 

When they returned, Grunkle Stan was waiting for them on the porch. As soon as he saw them walking out of the woods, he fixed them with a gaze like a tractor beam, making it clear he wasn’t to be avoided. Dipper pulled down the brim of his hat to hide his eyes, which Mabel had called “demonic and creepy, but kick-ass for a Halloween costume.” Even if they did end up telling Grunckle Stan what happened in the woods today, Bill sort of possessing Dipper (albeit with Dipper’s permission) was a detail he didn’t ever need to find out about. 

“Are you two okay?” he asked, in that gruff deadpan Dipper and Mabel both knew he used only when he was trying to hide genuine concern. “That demon didn’t do anything weird to you? I was about to call the cops after an hour, but they might have found the gold and…other things. Another few minutes and I was gonna go out and look for you myself."

“We’re totally fine,” Mabel assured him. “Bill was actually really helpful, but Dipper feels kind of sick, so I’m going to go upstairs with him and put him to bed.”

Dipper coughed and hacked on queue – quite convincingly, he thought. 

“Sick, eh? That was sudden,” Grunkle Stan said suspiciously. But he didn’t press the point, seeing as the twins had returned in one piece (and with no conspicuous extra pieces). “Where is that demon, anyway? When he gets back here I’m gonna give him a piece of my mind." 

_‘Don’t even think about it,’_  Dipper thought, when he felt Bill’s interest pique. 

**_Aw, you Pines’ are all out to spoil my fun_** _,_ Bill sulked. 

Once they were inside, Dipper had to force himself to walk to the stairs at a deliberate pace when what he wanted most was to spend his last reserve of energy in a mad dash up the stairs and fall into his bed to sleep and wait and and let time begin its healing. Mabel insisted on tucking him in and asked if he wanted some water, tea, pancakes, more hugs, a sweater and about a thousand other things before Dipper could finally stop her. 

“Mabel,” he said, “I’m fine. And you shouldn’t be waiting on me when you went through even more than I did.”

“I feel fine," Mabel assured. "And I’m really sorry, Dipper.” She cast her eyes down, twisting the sleeve of her sweater in her fingers. “I’m sorry I let Alexandra get to me. I can't help thinking I caused all of this, in a way.”

That had Dipper sitting up again, fast. “Mabel, I know you don’t really remember it, but when I saw your memory of meeting Alexandra, the way you talked to her… You were so strong, and brave. There was no way you could have stopped her from forcing you into a fake deal, but I was so proud to have you as a sister in that moment, and I still am. You did nothing wrong. If anything, it was my relationship with Bill that made you more of a target.”

“Aw, no, Dipper,” Mabel said, wavering between a smile and a frown. “We both knew the risks with Bill, and they were worth it because he made you so happy. And I know that now you remember things about him that I don’t, but…I hope you haven’t forgotten how happy you’ve been, either.”

“I haven’t forgotten,” Dipper said, holding out his arms. “And I’ve changed my mind. I do want more hugs."

Mabel burst into a teary smile and hopped onto the bed, wrapping her arms around Dipper and burying her face in his messy hair. 

**_Hey, you guys both know I’m still here, right?_**  

_‘Shh!’_  Dipper hissed in his head, holding Mabel tighter. He had been so scared he would lose her… 

Finally, Mabel pulled away and slid off the bed. “Get some rest, Brobro. I’ll bring lunch up later.” 

“Thanks, Mabel,” Dipper said, settling back into bed. “Love you.” 

“I love you, too, Dip-dop,” she said, blowing him a big kiss before she left and closed the door behind her. 

Dipper sighed and closed his eyes, letting his head sink into the soft pillow. His headache had gotten bad again, and thinking was only making it worse. He wanted nothing more than to drift off into unconsciousness. 

**_Hey, Pine Tree._**  

_‘Ugh, not now, Bill.’_

**_Yes now, kid. That sleeping thing you’re planning on doing? I really wouldn’t recommend it._ **

_‘Why? Because you won’t be able to have any fun controlling me if I’m asleep?’_ It was kind of a mean thing to say, and Dipper didn’t think that was Bill's reason at all, but he was tired and in pain and he just wanted take a break from reality for awhile. 

Dipper’s headache increased somewhat, though Bill sounded only mildly peeved at Dipper’s response rather than offended or angry. Of course he would know Dipper didn’t intend to be hurtful – he was in Dipper’s head.  ** _No, but you know what I can’t control while I’m in here? The other big nasties of the Mindscape. The manifestations of terror, wrath, envy, and things much older, and much worse. I could protect your mind from them if I were even half my usual self, but I’m running on empty here. As things stand, I’m a match for the worst of them, and I don’t want to trust your sanity to a coin toss._**

Dipper thought about this, though – as previously mentioned – thought was not his strong suit at the moment. The first thought that came to him was that Bill seemed to be placing Dipper’s well-being above his own. But then he pieced together the bigger picture, and it was all he could think about.  _‘What about the millions of other people in the world who are already asleep?’_

**_There aren’t many creatures in my domain that can do harm outside of it, but with so many dreamers, odds are, about a thousand will lose their minds or their lives before I’ll be able to rein the dogs back in._ **

“A thousand people?” Dipper gasped, unable to keep himself from saying the words aloud. “I…I can’t let that happen. Is there any way we can get you back into the Mindscape more quickly?”

**_Sorry, kid_** _,_ Bill said, and he did sound sorry.  ** _This is one thing you can’t fight. You can’t save people from their own minds._**

Dipper groaned, feeling like he wanted to throw up but didn’t have the energy. He wanted to try, to do  _something_  – pull out the journals, interrogate Bill until they came up with an idea, even have Bill send him into the Mindscape himself if it was possible – but he just couldn’t quite muster the resolve. He felt so drained, almost empty, and he couldn’t even bring himself to care properly about the thousand anonymous victims across the globe who would be caught up as the last collateral damage in Bill and Alexandra’s war. 

**_It’s okay, Pine Tree. This one’s out of your control. It doesn’t make you less human to let it go._ **

A few silent tears rolled hot down Dipper’s cheeks, but apparently he didn’t even have the energy to cry properly. He took a deep, shaky breath and tried his best to do as Bill said and put it out of his mind. He didn’t know if it was the right thing to do, but it was the only thing he could do. 

_‘Okay… So if I can’t sleep, I can’t save people, and I can’t do much else… Do you want to talk?’_

**_Sure. What do you want to talk about?_ **

Dipper curled up on his side, getting as comfortable as he could.  _‘Well, I guess I first have to ask if you’re okay. I mean, you just killed your sister. Hopefully.’_  Dipper winced at how that sounded, but he knew Bill knew what he meant. He just hoped that what Bill did had worked once and for all. 

**_Kid, I feel sorrier for the deer_** _,_ Bill said airily.

Dipper still felt a little horrified by Bill’s apathy towards his sister, but he also felt he was beginning to understand it. Demons really weren’t human – to think of them that way was both dangerous and foolish. 

**_Listen, you’ve gotta believe me when I say that Alexandra and I had nothing like what you and Shooting Star have. You two have something really special, Pine Tree. What she and I had was just…rotten._ **

_‘Yeah, after all that, I believe you.’_ Dipper lapsed into silence for awhile and let his heavy eyelids close, though he was no longer drowsy, and so didn’t risk falling asleep.  _‘So,’_  he thought finally,  _‘what about what we have? You said you love me. And you meant to say it.’_

Dipper felt Bill do the mental equivalent of cringe, but when he finally responded, all he said was,  ** _I did._**

_‘And I’m prepared to believe you – believe that, for whatever reason, you’ve changed…’_

**_I haven’t changed_** _,_ Bill cut in.  ** _I’m still the same demon who did all of those things to you and your family, and neither of us should forget it. I’ve just…learned a few things since then._**

_‘I thought you were supposed to know everything already.’_  Dipper couldn’t stop himself from thinking the sarcastic reply. 

**_So did I._ **

For once, Bill sounded…small. And Dipper didn’t at all like it. He sighed.  _‘Can you make me a promise?'_  

**_A promise isn’t the same as a deal_** _,_ Bill warned.  ** _Promises can be broken._**

_‘I know. But apparently you can go back on deals, too. Like when you destroyed McGucket's laptop.’_  

**_Well, you got me there. But I’ve told you I don’t have to make deals to get what I want. That was just—_ **

_‘For fun,’_ Dipper supplied. 

There was a long pause.  ** _Yeah, kid_** _,_ Bill sighed. 

Dipper’s anger was dull and brief, though whether because of his current condition, or because he already knew he would forgive Bill, in time, he couldn’t say.  _‘Just promise me you won’t forget what you’ve learned.’_

**_Didn’t_** ** _I tell you my memory is flawless?_** Bill scoffed indignantly.

Dipper smiled weakly, despite how awful he felt.  _‘Yeah, I guess you did. So that’s a promise?’_

**_That’s a promise._ **

Dipper hummed, content with that for now.  _‘Thank you for what you did today. You risked a lot to protect Mabel and me.’_

**_Well that’s one thing my sister got right about me. I protect my own interests first. As of very recently, that includes you and Shooting Star._**  

_‘That’s one way to put it,’_ Dipper mused.  _‘Another is that you did something selfless.’_

Dipper’s headache increased marginally more, and he shut up. 

**_Is there anything else? If not, you need your rest. I can put you into a restorative trance while keeping you awake until I can blow this popsicle stand._ **

That sounded… really quite nice. But there was one more thing.  _‘You know Mabel and I go back home in three days. I think the time apart will be good for us – or me at least, to let the memories age as they should have. And then, when I come back next summer, if you’re still here…’_  

**_I will be._**

“Is that another promise?” Dipper breathed. 

**_It is. You’re getting me into a bad habit with this promising thing_** _,_ Bill complained. 

That was the last thing Dipper could remember before a pleasant, relaxing fog subsumed him, taking with it pain and awareness. 

☆

When his awareness returned, the first thing he noticed was a sandwich on a plate on his nightstand, with a green Post-It proclaiming in purple marker, “You look like a sleeping kitten, so I’ll just leave this here — Mabel,” with a fat heart in the bottom corner. The next thing he noticed was that he felt like his usual self again. There was no more pain, exhaustion, or that cannibalistic emptiness at his core. Even his headache was gone. Which led him to notice the third thing. 

_‘Bill?’_  he tried. 

“Hiya, Pine Tree!”

Dipper started and turned over to see Bill lying on top of the blankets beside him, his hands behind his head and a big grin plastered across his face. A face that, thankfully, no longer bore a mystical light-leaking crack from hairline to jawline. 

“Bill!” Dipper exclaimed, relieved. He threw his arms around the demon before his old instincts could scream at him to stop. He ignored them when they did. “The Mindscape monsters, are they…?" 

“They turned tail and fled as soon as they sensed I was back in business. They aren’t stupid.” Bill sounded a lot like his usual self, too, but he still seemed…tired, somehow. Whatever enchantment Dipper had used on him and his sister, evidently it had a long recovery process. 

“Thank god,” Dipper sighed into Bill’s shoulder. 

“Hey, you should be thanking me!” Bill whined, pulling back. 

Dipper chuckled. “Thank you.”

“You can really thank me by letting me have half of that sandwich,” Bill said.  

Dipper examined the demon suspiciously. “I thought you didn’t like sandwiches,” he said.  

“I don’t like  _your_  sandwiches,” Bill said, poking Dipper’s chest with a finger. “Shooting Star’s are delicious.”

Dipper grumbled a little for pretense, and then they split Mabel’s sandwich and spent the rest of the afternoon lying in bed together until it was time to go down for dinner. What Bill called 'being space efficient', Dipper would have called 'spooning,' but he knew Bill would vigorously deny any such accusation. 


	13. Home

Dipper and Mabel sat on the old, wheezing, empty bus to Gravity Falls, nine months after they had left. This trip was just like the many others before it, including, they suspected, the same exact bus, but there was the notable addition of fresh veins of anxiety running through their usual excitement. They had just finished their senior year of high school; college awaited them at the end of summer, and with it, uncertainty. Who knew what new rhythms their lives would take once they began living away from home, and each other? This may very well be their last summer in Gravity Falls like the ones they had had as kids. They would of course visit their Grunkle as often as they could get away with, but they both knew, though neither said it aloud, that it would never be quite the same after this. 

Dipper’s anxiety was double, as this was the first time he would see Bill in almost a year. They had had not even two months together, and then nine apart. Bill could have visited Dipper during the school year of course – he wasn’t bound to Gravity Falls – but Dipper had requested time and distance, and Bill had given it to him. Nine months was probably nothing to a creature as old as Bill Cipher, but it was a long time for Dipper, and there were days when he regretted making that request. But overall, he was able to focus on school and spend time with his parents and his friends who he would probably never see again after high school (he was only being realistic – they weren’t that good of friends). He graduated second from the top of his class (that suck-up Norman had revised and submitted one of his final papers for re-grading on the last day of school and pulled his GPA above Dipper’s by 0.01), and he was proud of himself for not only surviving high school, but leaving all of the kids who were less than kind to him in his dust, taking no scars away from the four-year experience. They could fight each other over impacted courses in the Cal States and community colleges for the next six years for all Dipper cared. Still, even with all the stress of senior year, Dipper couldn't recall having a single nightmare. 

Dipper didn’t tell his parents about Bill, and he doubted if he ever would. His parents loved him and Mabel unconditionally, and he loved them the same, but he never told them about the anomalies of Gravity Falls. He and Mabel often joked that the little town was like Las Vegas – what happened there stayed there. No one else would understand. Grunkle Stan sent them a few letters over the course of the year and sometimes he would mention Bill briefly, if only to say that the demon hadn’t burned the place to the ground yet. In one of the earlier letters he said that Bill was even helping out at the Shack a few days a week in the twins’ absence, and that he was surprisingly popular with the tourists, if not always entirely responsible with them. He would occasionally return with one of his tour groups in which the children would be jumping and running around yelling excitedly and unintelligibly about the amazing things they had seen, while the adults returned silent, trembling and pale as a sheet. Still, they tipped well, so Grunkle Stan didn’t look into the matter too closely. 

Bill apparently went by William with the tourists, and he told a different but equally creative story to anyone who asked about his strange appearance. Dipper smiled when he read that part. He could imagine it so easily. He had always loved Bill’s stories, even when they started out as what were supposed to be serious answers to some of his questions. At least when Bill decided not to tell him something, he put a lot of effort into coming up with an alternative that Dipper was certain must be at least more _entertaining_ than the truth. 

Of course, all that meant that the only person he could talk to about his long-distance relationship with the dream demon was Mabel, and she got a little sick of playing relationship counselor to her brother after the first few months. But even then, she tolerated his rants and worries with truly admirable temperance and understanding, and Dipper really thought someone should give her a medal of valor. He might have even requested that the Vatican canonize her if he didn’t still have stolen clerical vestments from St. Peter’s in the back of his closet. 

The tables would be turned in Gravity Falls, though, as one of Mabel’s friends had grown to be a little more than that in the last half of the school year, and now she would have to deal with the long-distance thing herself. At least the two of them were going to the same college. Dipper had known him peripherally, and he had always liked him. He was certain it didn’t hurt that the guy had finally come out of his awkward phase, and grown considerably more attractive over junior summer. If Dipper didn’t already have someone quite special, who also happened to be literally hot as sin, he might have even been a little jealous. Still, Mabel could have chosen to spend the summer with her new boyfriend back in California, and instead she had eagerly boarded the bus to Gravity Falls with Dipper without a backward glance. 

Now, she was holding his hand on the seat between them. The small gesture was deeply reassuring: come what may, they would never be separated for long. 

“Gravity Falls,” the bus driver announced, and the old PA system made his voice echo almost like Bill’s. 

A shiver ran through Dipper at the sound, and he couldn’t decide whether it was good or bad. Probably some of both. He had forgiven but not forgotten, as Bill himself had advised, and he really had no idea how he or Bill would react when they first saw each other again after so long. 

He and Mabel hopped off the bus and hauled their bags out of the undercarriage, and a minute later they heard the distinctive growl-and-rattle of Grunkle Stan’s old station wagon pulling into the lot on the other side of the bus. When the bus pulled out, Grunkle Stan was standing there, looking just about the same as always – warm and homey in the way that a familiar old study with cheap cigars in the ashtray was – and beside him stood Bill, looking…really like nothing else. Bill would always just be Bill, with all of the multiplicity and complexity that entailed. Of course, he looked exactly the same. Dipper would have sworn that that black top hat and bowtie, yellow coattails and vest, white dress shirt, black leather gloves and black slacks and shoes were glued to Bill’s person if he hadn’t personally removed them on numerous occasions. 

Great, now Dipper was blushing and Bill hadn’t even said a word to him yet. 

He and Mabel trudged across the bus bay to where Bill and Grunkle Stan were waiting in the parking lot, and when Dipper made eye contact with the demon, he swore Bill’s eye lit up. That familiar sharp, apex predator grin spread across his face, and Dipper really didn't know when he had somehow begun to find it reassuring.

He smiled and waved back, and then Mabel was running to hug Grunkle Stan, forcing her suitcase to keep up with her. Dipper didn’t quite have the ability to beat inanimate objects into submission that she did, but soon enough he was standing in front of the demon, still puffing embarrassingly from the effort of the crossing (he always brought about half his bookshelf with him for the summer). 

“Can I get that for you, Pine Tree?” Bill said, stifling a chuckle. 

“Yeah, th-thanks,” he said dumbly.

Bill leaned down to take the handle of the suitcase from Dipper, bringing their faces quite close together. Instead of pulling back once he took the suitcase, however, Bill met Dipper’s eyes and held his gaze a moment. “May I?” he whispered. 

“God, yes,” Dipper breathed, and then Bill’s mouth was moving against his. Dipper wrapped his newly unoccupied arms around Bill’s neck, and Bill promptly dropped Dipper’s suitcase to snake his arms around the teen’s waist and pull him closer, deepening the kiss. Dipper could practically taste Bill’s desperation, and he was sure he wasn’t much better.  At least when Bill murmured “I missed you” against his lips, Dipper knew he meant it. So, nine months hadn’t been nothing to the demon after all. Dipper couldn’t help but feel immensely satisfied. 

He was vaguely aware of Grunkle Stan grumbling to Mabel, “Great. I’m now chopped liver next to a damn demon.”

It was enough to pull Dipper out of his haze, and he gave his Grunkle an apologetic look before he whispered to Bill, “More later.”

“Is that a promise?” Bill asked, picking up his suitcase again. 

Dipper gave a grin to rival one of Bill’s. “Absolutely.”

Then he turned to Grunkle Stan and gave him a proper greeting, which in the Pines twins’ book meant hugging him until the air was squeezed out of his lungs and he wheezed, “I regret I said anything.”

Bill and Grunkle Stan threw the luggage into the trunk of the car and they were about to leave when they heard Lazy Susan’s distinctive voice yell to them in noisy greeting. Mabel and Dipper looked at each other in vague confusion, as their family and the woman had never been all that close, though she had always been kind to them. She was out shopping, judging by the bags in her arms, but she was actually coming over to talk to them. Dipper was even more confused when Bill tipped his hat to her in a rather familiar manner. 

“The Pines twins are back!” she said excitedly. 

“Uh, yeah!” Mabel said, giving back a bright smile and punching the air. 

“You _must_ bring the whole Mystery Shack gang to my diner soon for a welcome home dinner,” she said to Grunkle Stan. “You can all have all the pancakes you can eat, on the house!”

“Wow, thank you, Lazy Susan,” Dipper said, because he knew that whatever Grunkle Stan had been about to say, his version would be more sincere, and less potentially offensive. “Is there an occasion for such generosity? Mabel and I come back here every summer.” 

“Well, your friend, William has really been the generous one,” she said. “He’s been telling all of the old Shack’s visitors that I serve up 'the most edible prepared foodstuffs on a plate in town'. I’ve never done better business!”

“Wow, William, that’s…really nice,” Dipper said to Bill, both confused and suspicious. He looked to Grunkle Stan, who only gave an unhelpful shrug. 

“Anyway, I’ve gotta run,” Lazy Susan said, “but it’s good to see you two back in town.” She gave a cheery wave and continued on her way. 

Grunkle Stan rolled his eyes and dropped into the driver’s seat, closing the door. 

“It’s the least I can do to make up for making her fall into a wood chipper once,” Bill said to Dipper behind his hand. 

Dipper looked at him, aghast.

“You saw her, she’s fine! I fixed her,” Bill said defensively.

Dipper’s eyes narrowed, but he decided to let it go. She did seem perfectly fine. In fact, thanks to Bill, she seemed downright chipper… And he really hadn’t meant to make that pun; what was he becoming? He sounded like Bill. 

“I swear I will never understand your boyfriend, kid,” Grunkle Stan sighed to Dipper when he'd settled into the backseat next to Mabel, and Bill had taken the passenger's seat. “One day he’s setting things on fire because he misses you, and the next he gets us all invited to a free pancake dinner.” 

Mabel made a strange gurgling noise. “You were driven to pyromania out of loneliness?” she gasped. “That’s so cute! In kind of a scary way.”

Bill glared across at Stan. “You traitor,” he said.  

“It was a brand new pool table,” Stan replied spitefully, turning out of the parking lot. 

“You had me teleport it into the storeroom from a bar in the next town over!” Bill shot back. “It was an abuse of my services is what it was, and you can only get away with so much because of your grandnephew. I’ve got my eye on you, Pines.”

“Well, I think that’s kind of…surprisingly romantic,” Dipper said. 

“Why surprising?” Bill asked, turning around to face him. “I can be romantic. I have many sides, Pine Tree.”

“I thought you had three,” Dipper said, deadpan. 

Bill was silent for a moment, then he blinked once, and finally he burst into laughter, so loud and sudden that Grunkle Stan cursed and swerved the car. Bill raised a gloved hand to wipe tears from his eye. "Aw man, Pine Tree," he sighed, "that was beautiful."

"Nooooo," Mabel mourned, looking pleadingly at Dipper. "Don't let Bill's weird geometry humor infect your mind."

"It's too late for him. Give it up, Shooting Star," Bill cackled, turning on the radio with a snap of his fingers.  Taylor Swift came on, and to all of their surprise, Bill didn’t change the station. In fact, he began humming along. 

_Nice to meet you, where you been? I could show you incredible things. Magic, madness, heaven, sin—_

“Nuh uh, I veto,” Grunkle Stan said, reaching to change the station. 

“Don’t you dare silence the voice of my generation!” Mabel cried, with such menace that Stan was shocked into inaction. 

Bill chuckled as the song continued: _Love’s a game, wanna play? New money, suit and tie, I can read you like a magazine. Ain’t it funny, rumors fly? And I know you heard about me. So hey, let’s be friends. I’m dying to see how this one ends. Grab your passport and my hand…_

“I could make the bad guys good for a weekend,” Mabel sang along, unsurreptitiously swatting the back of Bill’s head, causing him to scoff and roll his eye. Then she launched into the chorus with Taylor. Halfway into the song she got really into her impromptu karaoke, snatching Dipper’s hat off his head to stand in for a microphone and singing at the top of her lungs, “Screaming, crying, perfect storms. I could make all the tables turn. Rose garden filled with thorns. Keep you second guessing like, 'oh my god, who is she?' I get drunk on jealousy. But you’ll come back each time you leave– Bill this one’s yours!”

“‘Cause darling I’m a nightmare dressed like a daydream,” Bill chimed in enthusiastically. 

Until that point, Dipper had been content just to watch the hilarity unfold, but when Bill joined in, he figured to hell with it, and began singing, “So it’s gonna be forever…”

“…or it’s gonna go down in flames,” Bill sang. 

“You can tell me when it’s over…” Dipper sang. 

“…if the high was worth the pain,” Bill sang. “Got a long list of ex-lovers, they’ll tell you I’m insane,” he cackled. “‘Cause you know I love the players, and you love the game!” He pointed to Dipper. 

“‘Cause we’re young and we’re reckless,” Dipper picked up, “we’ll take this way too far. It’ll leave you breathless…” 

“Or with a nasty scar,” Bill cut in. “Got a long list of ex-lovers, they’ll tell you I’m insane.”

“But I got a blank space, baby,” Dipper sang, “and I’ll write your name.”

“Boys only want love if it’s torture,” Mabel took the bridge, and carried it through to the final chorus, which Dipper and Bill completed together, not even noticing that Mabel had dropped out and was watching them sing to each other with a big, goofy grin on her face. 

After belting the last four lines with Bill, Dipper was panting and giggling and generally feeling just about as happy as he’d ever been. 

“…I don’t know what just happened, but it never happens again in my car,” Grunkle Stan said gruffly after clearing his throat. But the twinkle in his eye betrayed the smile he was holding back. 

"Bill, why do you know the lyrics to that song?" Mabel asked, her smile half shrewd and interrogative, half big, dopey grin. 

"Uh, omniscience," Bill said, after a suspicious pause. "Anyway! Where are you two going to college? No one's told me." It was an obvious diversion, but everyone was willing to let Bill get away with it for once. 

“Well,” Dipper said, running a hand through his hair and still feeling rather sheepish from his unintentional duet with the demon, “Mabel’s going to a prestigious design school in New York—" Mabel made a dismissive gesture at that, but didn't deny it " — but I’ll be at Reed in Portland, that city you lied and told Grunkle Stan you were from.”

“No, Cipher said he was from ‘Port-Land’,” Grunkle Stan chuckled. 

“Where do you think the name came from, neophyte?” Bill growled. “I hardly see the difference.”

Dipper laughed. “Anyway, I wanted to be closer to home.”

They pulled off the long forest road then and stopped in front of the Mystery Shack – the same rickety old structure it always had been, complete with patched siding, crooked floors and signage perpetually missing its “S”. Just the sight of the old deathtrap made Dipper feel warm and safe.

“California?” Bill asked, confused. 

“Gravity Falls,” Dipper said with a smile. 

All it took was Bill’s bright, genuine smile in response, and suddenly, Dipper knew things were going to be alright. 

**Notes for the Chapter:**

> Yes, I ended this fic with Bill and the twins singing Taylor Swift in the car. No, I don't know what came over me. Sue me.

**Author's Note:**

> Thanks for reading! If you enjoyed my writing, you can commission a story from me here: http://urban-sorcerer.tumblr.com/commissions


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